Voters across the state will go to the polls in November to decide the fate of rent control in Massachusetts, thanks to a Supreme Judicial Court ruling yesterday declaring a referendum on the issue legal.

If the electorate outlaws rent control, the ban would affect 16,000 Cambridge households--half its rental stock--and a quarter of the city's population, said Terry Morris, executive director of the city's Rent Control Board.

The decision represents a major victory for group seeking to ban the price ceilings. Activists had made several unsuccessful attempts to end rent control through the State Legislature and various city councils.

Meanwhile, rent control advocates said they are upset about the setback, but vowed to fight on.

The court ruled that a referendum on rent control does not violate the "home rule" provision in the state constitution.

The home rule clause says that an initiative petition cannot bring to the voters any measure whose operation is restricted to one or a few towns in the state.

The city of Cambridge and several activists filed a complaint charging that a referendum on rent control infringed on this right, and a hearing was held on May 5. The suit came in the wake of a petition calling for a vote on the price ceilings.

The city argued that a vote would be illegal since rent control is presently in effect in only three municipalities--Boston, Brookline and Cambridge.

In other words, the city said it would be unfair for the entire citizenry of Massachusetts to make this decision, when its results would impact just three cities.

But the court ruled that the rent control ban is not simply a local issue. In the nine-page decision, the court noted that the it is "within the power of a municipality to enact a rent control program only when the [State] Legislature has explicitly delegated that power to the municipality."

Rent control is thus an issue of statewide concern and is hence subject to the initiative process, the decision said.

If Massachusetts voters do throw out rent control, municipalities could still, in fact, implement it on a voluntary basis.

But Denise A. Jillson, president of the anti-rent control Massachusetts Homeowners Coalition, said last week that there would be a big difference.

"There will be strict guidelines, putting responsibility on the city or town," Jillson said.

For example, she said, if a city decided to implement rent control, it would have to compensate home owners for the difference between the ceiling and the market price.