Opinion by
Mr. Justice Jones,In 1958, Samuel Cox and a codefendant pleaded guilty in the then Court of Quarter Sessions to a series of eleven armed robberies, having been represented at their joint trial by a court-appointed attorney. Both men were sentenced to serve two consecutive terms of ten to twenty years in prison, plus a ten-year period of probation at the end of the jail sentences. In 1964, Cox filed a petition for a writ of habeas corpus in the Court of Common Pleas of Philadelphia County. This petition was dismissed upon a finding that the guilty plea had been knowingly and voluntarily entered and, on appeal, the Superior Court affirmed the judgment of sentence. Commonwealth ex rel. Cox v. Myers, 206 Pa. Superior Ct. 705, 211 A. 2d 545 (1965). We refused to grant allocatur.
Cox next sought relief by petitioning for a writ of habeas corpus in the United States District Court for the Eastern District of Pennsylvania. A lengthy evidentiary hearing was held on June 7, 1966, during which both Cox and his original counsel testified about *68the trial and the sentencing proceedings. That court held that the petitioner’s constitutional rights had not been violated and his federal habeas corpus petition was denied and dismissed on June 14, 1966. United States ex rel. Cox v. Myers, United States District Court, Miscellaneous No. 3196 (E.D. Pa. 1966).
Cox initiated the instant proceedings, with the aid of an attorney by a petition filed in July of 1967, pursuant to the Post Conviction Hearing Act. Cox claims that he was denied the effective assistance of counsel at the time of sentencing in May of 1958. A hearing was held on November 18, 1968, during which no further evidence was offered beyond the transcripts of the testimony taken in prior proceedings. This petition was denied by the Court of Quarter Sessions of Philadelphia County and the Superior Court affirmed that order on June 24,1969. Commonwealth v. Cox, 214 Pa. Superior Ct. 470, 257 A. 2d 331 (1969).* We granted allocatur.
A defendant does not waive his opportunity to litigate issues not raised in earlier post-trial proceedings where he was not represented by counsel in the prior proceedings. Commonwealth v. Johnson, 433 Pa. 582, 252 A. 2d 641 (1969). If he was so represented, then he may thereafter be barred from attacking the judgment of sentence. Commonwealth v. Black, 433 Pa. 150, 249 A. 2d 561 (1969). Cox was apparently without an attorney in the 1964 habeas corpus proceedings. Therefore, he may still assert that he was ineffectively represented at the time of sentencing, due to his attorney’s alleged conflict of interest.
The trial court did not have the aid of a presentence investigation, and the only comment made by the attorney who represented both men was that Cox was twen*69ty years old and Ms codefendant was twenty-eight. Cox’s trial counsel testified that, in view of the numerous robberies which were involved, he believed that any attempt to present Cox as a mere misguided youth would be fruitless and might antagonize the sentencing judge. Had Cox been singly represented, Ms attorney could have pointed out that the codefendant was a deserter from the Navy with a long criminal record, whereas Cox was a Mgh school graduate, had been honorably discharged from the Army and had no prior criminal record.
“If, in the representation of more than one defendant, a conflict of interest arises, the mere existence of such a conflict vitiates the proceedings, even though no actual harm results. The potentiality that such harm may result, rather than that such harm did result, furMshes the appropriate criterion.” Commonwealth ex rel. Whitling v. Russell, 406 Pa. 45, 48, 176 A. 2d 641, 643 (1962). However, the mere fact of dual representation does not per se indicate a true conflict of interest. Commonwealth v. Wilson, 429 Pa. 458, 240 A. 2d 498 (1968). We must still determine whether the record indicates that the defendant was adversely affected, i.e., whether he was deMed the effective assistance of counsel due to the dual representation. Commonwealth v. Resinger, 432 Pa. 398, 248 A. 2d 55 (1968). See Commonwealth ex rel. Washington v. Maroney, 427 Pa. 599, 235 A. 2d 349 (1967).
A conflict may be established if a defendant can show either: (1) that he had a substantial defense, wMch was not raised, that was inconsistent with that of his codefendant; or (2) that counsel neglected the defendant’s case in order to concentrate on that of Ms codefendant. Commonwealth v. Wilson, 429 Pa. 458, 463, 240 A. 2d 498, 501 (1968). Accord, Commonwealth v. Williams, 435 Pa. 550, 257 A. 2d 544 (1969).
*70Prior to meeting Ms codefendant, Cox had had a relatively good history, and the presentation of that Mstory to the sentencing court would certainly have east his codefendant in an unfavorable light. The record indicates that defense counsel was faced with a true conflict of interest wMch prevented him from adequately representing Cox at the time of sentencing. Accordingly, Cox is entitled to be resentenced with the assistance of counsel. See United States ex rel. Thompson v. Rundle, 294 F. Supp. 933 (E.D. Pa. 1968).
We wish to make it abundantly clear that we do not reach this result on the basis that Cox and his codefendant received the same sentence. The lower court is imbued with broad discretion in the matter of sentencing. See United States ex rel. Hairston v. Myers, 237 F. Supp. 472 (E.D. Pa.), cert. denied, 381 U.S. 943 (1965); Commonwealth v. Zelnick, 202 Pa. Superior Ct. 129, 195 A. 2d 171 (1963), cert. denied, 377 U.S. 1006 (1964). We merely find that there was a conflict of interest which may have prejudiced Cox at the time of sentencing. He is entitled to be resentenced with the aid of an attorney who faces no such conflict.
Order reversed. Record remanded for proceedings consistent with tMs opiMon.
Mr. Justice Eagen and Mr. Justice Robeets concur in the result. Mr. Justice Cohen dissents.Judge Hoffman filed a dissenting opinion, in which Judge Spaulding joined.