The Cambridge rent control referendum campaign suffered an all-but-fatal blow yesterday afternoon. Middlesex County Superior Court Judge Henry Leen ruled that a rent control referendum cannot appear on the City's November 4 election ballot.

Cambridge City Solicitor Philip M. Cronin said last night that Leen had dismissed a writ of mandamus petitioned by members of the Peace and Freedom Party and the Cambridge Housing convention. The writ asked the court to overturn a ruling by the Cambridge Election Commission that the rent control bill is illegal and cannot appear on the ballot.

Members of the Peace and Freedom Party said last night they would appeal Leen's decision, but said it might be impossible to get a new ruling before the election. Ron Stoia, a member of the party. said that whatever the fate of the refereadum campaign, "people should enforce their own rent control." He said the party would continue to fight rent evictions.

City Councillor Barbara W. Ackermann, who favors some kind of a rent control bill for Cambridge, said last night that she and three other pro-rent councillors may make an offer to get some kind of referendum onto the ballot. She declined to elaborate, saying that she had not yet consulted the other councillors about the future of the issue.

According to Cronin, Leen's ruling was based on Article 47 of the Massachasetts Constitution which requires the State Legislature to give permission before a city can enact a rent control law. Leen could not be reached for comment last night.

Nothing to Do

Pro-rent control lawyers had argued that the issue of the legality of a measure has nothing to do with whether or not it can go on the ballot. A decision on the legality of the measure can only come afterits enactment and a challenge in court. they told a Superior Court hearing on Sept. 23.

The lawyers further argued that the election commission has no right to decide the legality of an issue but should merely perform the "ministerial" function of checking to find if all requirements for a referendum have been fulfilled.

The election commission's decision was based on an opinion by Cronin, who presented the case against a referendum at the Superior Court hearing.