OPINION OF THE COURT
CLAUSE, Senior Judge:Consonant with his pleas, the appellant was convicted of three specifications of robbery and one specification of assault in violation of Articles 122 (10 U.S.C. § 922) and 128 (10 U.S.C. § 928) respectively, of the Uniform Code of Military Justice. All four offenses occurred at the same time and place. The appellant and two companions who had weapons, approached the four victims, ordered them to surrender their money, collected it, then fled. As to the three victims whose money was taken, the appellant was properly charged with three separate offenses of robbery. As to the other victim, the offense was charged as assault. Appellant was sentenced to a dishonorable discharge, confinement at hard labor for four years and total forfeitures. The confinement portion of the sentence was reduced to three years pursuant to a pretrial agreement.
After acceptance of the accused’s plea, the trial proceeded to the sentencing phase. During the voir dire of the members, the defense counsel and a member engaged in the following dialogue:
“DC: Has any member of the panel been friendly with or had close association with Captain L., the prosecutor, in this case?
(Member raised his hand.)
DC: Colonel P., I believe Captain L., is assigned as your Staff Judge Advocate; is that correct?
MEMBER: That’s correct.
DC: Would you please state to me the day-to-day contact you’ve had with Captain L. and what his job is and what purpose he serves for you?
MEMBER: I’m convening authority for Corps Support Command. He provides *775advice to me in that capacity. He also tries cases associated with the members of my command. I see him twice a day.
DC: Thank you, sir. You will be instructed later on — comments for both the prosecution and defense are not evidence. Do you feel like any argument that Captain L. may make as to his theory of the case will be given more weight than the argument that defense counsel would give?
MEMBER: I don’t know you. I know him. I’m sure it will weigh. I don’t know how much.
DC: In other words .
MEMBER: I’ll treat them the same — try to treat them the same, but knowing Captain L. and his judgment, it might make an impact on me. I don’t know what it would be. Have to look at — I’d have to look at what was said in order to reach to that question.
DC: In other words, you have relied heavily on Captain L.’s judgment in the past and found him to exercise good judgment?
MEMBER: Absolutely.
DC: Do you feel like there may be some problems with — in the back of your mind about giving a little bit more weight to his?
MEMBER: I can’t make that judgment now, until I see what transpires.
DC: That possibility may exist if the evidence .
MEMBER: Could exist, yes.”
Based upon this colloquy, the defense counsel thereupon challenged the member for cause; the military judge denied the challenge without further questioning or comment. Appellant alleges before us that the military judge abused his discretion in his denial of the challenge.
Paragraph 62f of the MCM enumerates 13 grounds for challenge for cause. The 13th, or general category, excludes a member when “any other facts indicate] that he should not sit in the interest of having the trial and subsequent proceedings free from substantial doubt as to legality, fairness, and impartiality.” The determination of such grounds rests in the discretion of the military judge whose ruling will not be disturbed on appeal, absent an abuse of that discretion. United States v. Wright, 47 C.M.R. 637 (N.C.M.R.1973). He should, however, be liberal in passing on challenges.
An accused is entitled to a trial in which the military judge and members have a fair and open mind. United States v. Deain, 5 U.S.C.M.A. 44,17 C.M.R. 44 (1954). The test is whether the member is free to render an impartial sentence based upon the law and the evidence. United States v. Karnes, 23 U.S.C.M.A. 537, 50 C.M.R. 708, 1 M.J. 92 (29 August 1975), citing United States v. Parker, 6 U.S.C.M.A. 274, 284, 19 C.M.R. 400, 410 (1955). While a personal relationship of a familial or business character between a juror and a party, complaining witness or counsel may be disqualifying on the theory of implied bias, it appears that mere acquaintance with such persons does not disqualify a juror. United States v. Miller, 26 C.M.R. 570 (A.B.R.1958). There must be substantial doubt as to the legality, fairness and impartiality of the member.
The issue is further complicated in the case at bar by the fact that the trial counsel and the challenged member stand in the relationship of legal advisor and advisee that continued before, during and after trial. We recognize that the term “attorney-client relationship” is inapplicable here as that common law description excludes the type of association between a convening authority and his staff judge advocate. In the closest civilian analogue, we note that some jurisdictions have proscribed an attorney-client relationship in the statutory grounds of exclusion. See State v. McGraw, 6 Idaho 635, 59 P. 178 (1899). Others have noted that the relationship may be sufficient grounds for challenge if bias is shown. See Klinck v. State, 203 Ind. 647, 179 N.E. 549 (1932).
Although we determine that the association of the trial counsel and the challenged member is not a per se ground for *776challenge, we do not encourage the relationship as appropriate for a member and a counsel. The existence of such a relationship is certain to detract from the integrity of the court-martial and is a situation easily avoidable. We reject the notion, however, that the relationship is per se a ground for challenge absent any further showing. Actual or implied bias must be shown and the burden rests upon the challenging party to show it. Paragraph 62h, MCM. The mere assertion of the challenger is insufficient. United States v. Wright, supra.
It is the responses of the challenged member which creates a substantial doubt as to the impartiality of the proceedings. The member, who served as president of the court-martial, was unwilling to state that he would not be influenced by his special relationship with the trial counsel and the reliability he placed on counsel’s judgment. Nor would he speculate as to the extent of the possible influence this might have on his judgment. The member’s complete honesty in this regard is to be commended. We may not, however, speculate as to his impartiality in determining an appropriate sentence.* The appropriate remedy is a rehearing on sentence.
We note that the accused exercised his peremptory challenge against another member. Although there is a diversity of opinion as to whether or not the use of the peremptory challenge against another member waives the challenge for cause, we agree that it does not. United States v. Russell, 43 C.M.R. 807 (A.C.M.R.1971). The peremptory challenge is beyond examination for motive; it may be exercised for any reason or for no reason. That it was used is the only prerequisite for our consideration of the denial of the challenge for cause.
The findings of guilty are affirmed. The sentence is set aside and rehearing thereon may be ordered.
Judge DONAHUE concurs.Trial counsel’s novel argument on sentence relies heavily upon the acceptance of his sound judgment. Rather than stress the seriousness of the offenses counsel asserted that appellant’s prior good military record and civilian background demonstrated the need for longer confinement to effect his possible rehabilitation.