The. sole- issue raised by this appeal is the validity of the provision in the Seattle City Charter and civil service rules which limits eligibility for the city’s civil service examination .to United States citizens. We hold that such provision as applied to these plaintiffs constitutes an invalid interference with laws of the United States in a field of federal supremacy.
Plaintiffs appeal from a judgment of dismissal of their declaratory judgment action. The action seeks a decree (1) permitting plaintiffs to take civil service examinations and (2) enjoining Seattle city officials from discharging plaintiffs from their current employment, other than as provided for termination of employment of persons within the city’s civil service system.
Article 16, § 6 of the Seattle City Charter provides in part:
All applicants for offices or places in the classified civil service shall be subject to examination, which shall be public, competitive and open to all citizens of the United States with specified limitations as to residence, age, health, habits and moral character . . .
Civil service rule 4.01, adopted pursuant to charter authority, provides that in order to qualify for examination the applicant must be a citizen of the United States. Rule 7.07 allows provisional employment of noncivil service persons when there is no suitable eligible register of regular civil service personnel available. Such provisional employment is restricted to 60-day, renewable periods, pending availability of an “adequate eligible register,” and must cease within 21 days after notice that a regular civil service employee is available, unless an extension is granted by the secretary of the civil service department.
Plaintiffs are 18 residents and taxpayers of King County. Each is a “resident alien”, having been granted permanent residency in the United States by the United States Department of Justice.- During oral argument we were advised that each of the plaintiffs had filed his declaration of intent to become a United States citizen pursuant to federal nat*531uralization law. All are competent engineers who have been employed by the city of Seattle under “provisional” appointments for lengths of time ranging from about 1 year to more than 3 years. Being “provisional” employees, plaintiffs are subject to termination for no other cause than the certified availability of an eligible “regular” employee for his position.
The city recruited plaintiffs during a period of critical shortage of engineers in the Puget Sound area. Recruiting advertisements were broadly published in the city’s search for trained engineers. Plaintiffs moved to Seattle from other states (and in one instance from Canada) in response to this solicitation. They were not required to take civil service examinations at the time of their employment, but were employed as “provisional” employees under civil service rules.
In the fall of 1969, a register or list of persons eligible for permanent civil service employment in the positions held by plaintiffs was certified under the civil service rules. Faced with discharge under civil service rule 7.07, plaintiffs applied to take the examination for admission to the classified service. Each application was rejected, solely on the basis that the applicant was not a citizen of the United States. There is no issue as to the competency, character or work performance of any plaintiff.
Plaintiffs asserted to the trial court and here contend that the citizenship requirement of the city charter and the civil service rules is invalid on any one of five grounds: (1) conflict with the federal scheme under the Immigration and Naturalization Act of 1952, as amended (8 U.S.C. § 1101, et seq.); (2) conflict with the Washington Anti-discrimination Law (RCW 49.60); (3) conflict with the Civil Rights Act of 1870 (42 U.S.C.A. § 1981); (4) violation of the Due Process Clause (U.S. Const. amend. 14); (5) violation of the Washington and federal equal protection clauses (Const. art. 1, § 12; U.S. Const. amend. 14).
The protections of the Fourteenth Amendment apply to aliens as well as citizens. Truax v. Raich, 239 U.S. *53233, 60 L. Ed. 131, 36 S. Ct. 7 (1915). Further, enactments' of municipal corporations constitute “state action” within the Fourteenth Amendment. Avery v. Midland County, 390 U.S. 474, 20 L. Ed. 2d 45, 88 S. Ct. 1114 (1968). The meaning of these constitutional provisions in the context of aliens’ rights has been succinctly stated by Justice Murphy in his concurring opinion in Bridges v. Wixon, 326 U.S. 135, 161, 89 L. Ed. 2103, 65 S. Ct. 1443 (1945):
Since an alien obviously brings with him no constitutional rights, Congress may exclude him in'the first instance for whatever reason it sees fit. Turner v. Williams, 194 U. S. 279. The Bill of Rights is a futile authority for the alien seeking admission for the first time to these shores. But once an alien lawfully enters and resides in this country he becomes invested with the rights guaranteed by the Constitution to all people within our borders. Such rights include those protected by the First and the Fifth Amendments and by the due process clause of the Fourteenth Amendment. None of these provisions acknowledges any distinction between citizens and resident aliens. They extend their inalienable privileges to all “persons” and guard against any encroachment on those rights by federal or state authority.
We find it unnecessary to deal with each of plaintiffs’ contentions as we are of the opinion that the federal supremacy in the field of immigration as exercised by Congress precludes the city from establishing citizenship as a condition to eligibility for civil service examination for general public employment in occupations which have been designated as needed by the Secretary of Labor.1
The memorandum opinion of the trial judge makes clear that he felt compelled to his decision by language in our prior cases that “the state and the various municipalities within it have the right to say that public work shall be done in any manner, at any price, and upon any terms *533which they see fit to lay down.” Jahn v. Seattle, 120 Wash. 403, 406, 207 P. 667 (1922). Cornelius v. Seattle, 123 Wash. 550, 213 P. 17 (1923). The trial judge apparently felt precluded from the more modern and hospitable approach suggested in Purdy & Fitzpatrick v. State, 71 Cal. 2d 566, 456 P.2d 645, 79 Cal. Rptr. 77 (1969), because, as stated in his memorandum opinion, “Unfortunately, the Purdy case is not the law of the State of Washington nor of the United States, even assuming its applicability to the facts of this case.”
We do not read Jahn and Cornelius as establishing a rule of absolute discretion in state or local governments as to who will be allowed employment relating to public works. Jahn was a departmental decision in which we upheld a municipality’s power to require that private contractors on public works projects pay their employees at a rate no less than that paid by the municipality for work of like character. In the context of that issue,- we said:
Regulations on this subject suggest only considerations of public policy. And with such considerations the courts have no concern.”
In other words, the state and the various municipalities within it have the right to say that public work shall be done in any manner, at any price, and upon any terms which they see fit to lay down. It is in the power of the state and of its subsidiary municipalities to say that public work shall not be done, or that it may be done, and in the latter case it can prescribe the terms and conditions upon which it will allow it to be proceeded with.
Jahn v. Seattle, 120 Wash. 403, 406, 207 P. 667 (1922). We there also took note of then extant United States Supreme Court cases upholding provisions regarding nonemployment of aliens on public work. Heim v. McCall, 239 U.S. 175, 60 L. Ed. 206, 36 S. Ct. 78, Ann. Cas. 1917B 287 (1915); Crane v. People of New York, 239 U.S. 195, 60 L. Ed. 218, 36 S. Ct. 85 (1915). However, see Graham v. Richardson, 403 U.S. 365, 29 L. Ed. 2d 534, 91 S. Ct. 1848 (1971), wherein, in referring to Heim and Crane, the Supreme Court stated: “But this Court now has rejected the concept that constitu*534tional rights turn, upon whether a governmental benefit is characterized as a ‘right’ or as a ‘privilege.’ ” It should be clear from a complete reading of the Jahn opinion that our language had reference to situations where the subject matter suggests only those considerations of local public policy with which courts have no concern. The result and reasoning of the Jahn case were not directed to such other considerations as preemption by or conflict with superior law.
Cornelius v. Seattle, 123 Wash. 550, 213 P. 17 (1923), also a departmental decision, involved a city ordinance limiting the collection of swill from public eating places to responsible citizens of the United States. Unfortunately, in the course of that decision, we made the overbroad statement that Jahn “held” that a city may limit public employment to United States citizens. There, we stated at page 557:
It may be admitted without cavil . . . that the fourteenth amendment applies equally to aliens as to citizens. Yick Wo v. Hopkins, 118 U. S. 356; Wong Wing v. United States, 163 U. S. 228; United States v. Wong Kim Ark, 169 U. S. 649; Truax v. Raich, 239 U. S. 33.
We then concluded that the ordinance did not violate the equal protection clause of the Fourteenth Amendment. But to say that a city may limit public employment to United States citizens in some instances is not to say that such limitations are valid in all instances. Whatever the continuing validity of this conclusion, the present point is that Cornelius, even with its broad reading of Jahn, does not stand for the proposition that state or local governments are completely free to discriminate against aliens in public employment. Cornelius does not preclude courts from assessing such discrimination in the light of superior statutory law.
Thus, as we understand those cases, neither Jahn nor Cornelius grants an unrestricted license to discriminate against aliens in public employment.2 In neither case was *535there any asserted inconsistency with superior legislation. Moreover, the generations intervening since those cases have seen significant developments: first, with regard to application of the equal protection clause of the Fourteenth Amendment and, second, in the area of federal immigration and naturalization law.
Developments in constitutional equal protection indicate that discrimination in public employment on the basis of alienage invokes strict judicial scrutiny. We have already noted that the guarantees of the equal protection clause extend to aliens. Over the decades since John and Cornelius, supra, were decided, this concept has been expanded and clarified through application by our nation’s highest court. For one thing, it has become clear that states may not, without violating the equal protection clause, construct arbitrary classifications regarding qualifications for public employment. Wieman v. Updegraff, 344 U.S. 183, 97 L. Ed. 216, 73 S. Ct. 215 (1952); Whitner v. Davis, 410 F.2d 24 (9th Cir. 1969). Discriminatory classifications must be justified as reasonably related to, and a necessary means of accomplishing, the purposes of a law which promotes a compelling, legitimate state interest. Shapiro v. Thompson, 394 U.S. 618, 22 L. Ed. 2d 600, 89 S. Ct. 1322 (1969); McLaughlin v. Florida, 379 U.S. 184, 13 L. Ed. 2d 222, 85 S. Ct. 283 (1964); Takahashi v. Fish & Game Comm’n, 334 U.S. 410, 92 L. Ed. 1478, 68 S. Ct. 1138 (1948). See, generally, Developments in the Law—Equal Protection, 82 Harv. L. Rev. 1065 (1969).
Our purpose in tracing these developments is not to discuss constitutional arguments as they might pertain to this case. We do not reach the constitutional issues raised by plaintiffs. Rather, our purpose is to note the expanding *536application of equal protection principles to governmental actions. These developments serve to underscore two threshold points. First, discrimination solely on the basis of alienage, a process inconsistent with the principles of a free and open society, is also highly suspect under the specific constitutional precepts of the Fourteenth Amendment. Second, any such discrimination invokes strict standards of judicial review. To these we add the earlier observation that our case precedent does not foreclose a review of local provisions which discriminate as to public employment on the basis of alienage.
With the foregoing as background, we turn to the argument that these Seattle citizenship restrictions are an invalid interference with the authority of the federal government to control immigration. At the outset we reiterate the fact that we are dealing with a case involving qualifications for general employment. Conversely, this is not a case involving preferences in public employment or qualifications for public office, law enforcement, or policy making positions.
It is a matter of long established federal law that Congress has the exclusive power to regulate immigration and naturalization. U.S. Const. art. 1, § 8, clause 4; Hines v. Davidowitz, 312 U.S. 52, 85 L. Ed. 581, 61 S. Ct. 399 (1941); Fong Yue Ting v. United States, 149 U.S. 698, 37 L. Ed. 905, 13 S. Ct. 1016 (1893); accord: Purdy & Fitzpatrick v. State, 71 Cal. 2d 566, 456 P.2d 645, 79 Cal. Rptr. 77 (1969). State (and local) laws cannot substantially encroach upon this power. Truax v. Raich, 239 U.S. 33, 60 L. Ed. 131, 36 S. Ct. 7 (1915). Nor may state or local laws stand if they impede, burden or obstruct the full execution of a comprehensive congressional scheme regulating a particular aspect of immigration. U.S. Const. art. 6, clause 2; Nash v. Florida Indus. Comm’n, 389 U.S. 235, 240, 19 L. Ed. 2d 438, 88 S. Ct. 362 (1967); Hines v. Davidowitz, supra.
For our purposes, the relevant congressional scheme derives from the Immigration and Nationality Act of 1952, as amended (8 U.S.C. § 1101, et seq.). The import of this legis*537lation is well summarized in Purdy & Fitzpatrick v. State, supra, at page 82:
The Immigration and Nationality Act of 1952, as amended (8 U.S.C. § 1101 et seq.) provides that all immigrants, excepting immediate relatives of United States citizens or of lawfully admitted resident aliens, who seek to enter the United States for the purpose of performing skilled or unskilled labor shall he excluded unless the Secretary of Labor certifies that “ (A) there are not sufficient workers in the United States who are able, willing, qualified, and available at the time of the application for a visa and admission to. the United States and at the place to which the alien is destined to perform such skilled or unskilled labor, and (B) the employment of such aliens will not adversely affect the wages and working conditions of the workers in the United States similarly employed.” (8 U.S.C. § 1182(a) (14).) Although the Secretary may pass upon applications for certification upon an individual basis, more often certification depends upon preexisting determinations that certain occupations are experiencing labor shortages within the United States. From time to time, the Secretary publishes schedules of such occupations in the Federal Register.
In light of the comprehensive federal scheme for dealing with the admission of aliens who seek to enter the American labor market, any state [or local] legislation affecting this same subject matter runs a high risk of conflict with the supreme law.
(Footnote omitted.)
It is of more than passing interest that the California court used, as an example of clear conflict, a case where a state statute precluded architects and civil engineers (certified as needed by the Secretary of Labor) from employment on public works. In Purdy, the court was not faced with an actual conflict between state exclusionary law and federal regulation in this field. The court there struck down a California law proscribing employment of aliens on public works, because “[T]he opportunity for potential conflict is too great to permit the operation of the state law.” The facts now before us are more direct. Plaintiffs are civil *538engineers. As such, they have been specifically designated by the Secretary of Labor as persons possessing needed skills. 29 CFR § 60.6, schedule A (1969,1970).
Clearly, the federal scheme for immigration is intended to and does regulate alien employment to some extent. The schedule promulgated by the Secretary of Labor defines those aliens whose immigration to this country is desirable because they possess needed skills. This determination is not made in ignorance of local conditions; rather, in certifying the schedule, the secretary must consider the labor conditions in “the place to which the alien is destined.” 8 U.S.C. § 1182(a) (14). Whatever the wisdom of this part of the comprehensive federal scheme, the inescapable fact is that the determination is preempted by federal law and placed in the hands of the Secretary of Labor. We see no basis in the present facts for a suggestion that the secretary has exceeded proper limits in designating civil engineers within his schedule, and the city of Seattle makes no such suggestion. To the extent that Seattle’s local provisions discriminating against these aliens have the effect of deterring the execution of the federal law, those provisions intrude upon federal prerogatives and cannot stand.
It is asserted by the city that the instant facts are distinguishable from those in the Purdy case because (1) Purdy involved “ordinary” occupations, whereas this case involves engineers and, (2) Purdy involved a statute which proscribed all employment of aliens on public works, whereas the provisions here do not prevent employment but only the job-security (tenure) of civil service for aliens.
As to the first asserted distinction, we find nothing which militates in favor of thése discriminatory'provisions. To the contrary, the occupations of plaintiffs are within the schedule certified by the Secretary of Labor, while the occupations involved in Purdy were not so certified. From the standpoint of federal preemption, this difference favors plaintiffs rather than the city.
The second suggested distinction is premised on the fact that this citizenship restriction does not prevent em*539ployment of aliens, but only bars the tenure that would otherwise be available to them within the civil service. Implicit in this suggestion is the idea that while substantial denial of public employment would be an invalid intrusion on congressional authority,3 denial of job-security would not. We find this suggestion unrealistic. The provisional employment available to plaintiffs under the city’s civil service rules is uncertain at best, subject to termination at any time without cause and within 21 days of notice that there is an eligible candidate for the position. The result, though more indirect, is a very real interference with the opportunities of federally certified aliens to earn a living as public employees in the Seattle area. From the standpoint of encroachment upon the comprehensive federal scheme, this is a distinction without- a difference.
State and local governments can “neither add to nor take from the conditions lawfully imposed by Congress upon admission, naturalization and residence of aliens in the United States or the several states.” Takahashi v. Fish & Game Comm’n, 334 U.S. 410, 419, 92 L. Ed. 1478, 68 S. Ct. 1138 (1948). If labor conditions within the area render the federal scheme unwise as applied, then the appropriate remedy is with the federal officials concerned. We note, as did the California court in Purdy & Fitzpatrick v. State, 71 Cal. 2d 566, 456 P.2d 645, 79 Cal. Rptr. 77, 85 (1969), that Seattle “does not remain, therefore, without power to act, but merely without power to act with final authority upon a matter for which Congress has determined that one na*540tional policy administered by the federal government should prevail.”
Accordingly, we conclude that the citizenship restrictions of Seattle City Charter, art. 16, § 6, and of Civil Service Code 4.01 b(l), as applied in areas of general public employment, are invalid obstructions to the execution of the comprehensive federal scheme for immigration and naturalization. Our conclusion finds added support in the rationale of the recent pronouncement of the United States Supreme Court in Graham v. Richardson, supra. Plaintiffs are entitled to take the civil service examination..
Plaintiffs urge that upon taking the civil service examination, and assuming their success thereon, they should be afforded civil service status nunc pro tunc to the dates of their respective initial employment. But,, beyond the controverted assertion that the city “waived” the examination when hiring plaintiffs, there is no affirmative evidence on which to base a claim to such early status. The trial court found that plaintiffs were hired as provisional employees. We see nothing in the civil service rules which makes provisional hiring, for which examination is not required, ipso facto a waiver of examination to attain civil service status. Plaintiffs could have made application at any time and we see no injustice, absent countervailing evidence, in limiting plaintiffs’ potential retroactive status to such time as each would have been entitled had he taken and passed the first examination following his application. The trial court did not reach this issue and the record is inadequate for a determination by us.
Reversed and remanded.
Hamilton, C.J., Finley, Rosellini, and Stafford, JJ., concur.
As to the constitutional consideration, see Constitutionality of Restrictions on Alien’s Right to Work, 57 Col. L. Rev. 1012 (1957); The Alien’s Right to Work, 49 Col. L. Rev. 257 (1949); National Power to Control State Discrimination Against Foreign Goods and Persons: A Study in Federalism, 12 Stan. L. Rev. 355 (1960).
That which may already be obvious should be emphasized. In this case we are concerned with discriminatory limitations in general public *535employment as distinguished from employment which arises to the status of public office or position, a distinction which has long been recognized. E.g., Oceanographic Comm’n v. O’Brien, 74 Wn.2d 904, 447 P.2d 707 (1968); State ex rel. McIntosh v. Hutchinson, 187 Wash. 61, 59 P.2d 1117, 105 A.L.R. 1234 (1936); State ex rel. Allen v. Spokane, 150 Wash. 542, 273 P. 748, 277 P. 999 (1929); Nelson v. Troy, 11 Wash. 435, 39 P. 974 (1895). With that latter area we are not presently concerned.
See Truax v. Raich, 239 U.S. 33, 42, 60 L. Ed. 131, 36 S. Ct. 7 (1915):
The assertion of an authority to deny to aliens the opportunity of earning a livelihood when lawfully admitted to the State would be tantamount to the assertion of the right to deny them entrance and abode, for in ordinary cases they cannot live where they cannot work. And, if such a policy were permissible, the practical result would be that those lawfully admitted to the country under the authority of the acts of Congress, instead of enjoying in a substantial sense and in their full scope the privileges conferred by the admission, would be segregated in such of the States as chose to offer hospitality.