Since its inception in 1970, rent control has held center stage in Cambridge politics.

Other issues come and go, but the city's rent control system remains as controversial today as the day it was enacted. And in every election, rent control is a battleground between candidates favoring the system's overhaul and those rallying for its preservation at any cost.

This election year, however, the debate has a different spin, With three of rent control's strongest backers retiring from the City Council, the future of the system could be in jeopardy.

More importantly, city residents will vote this year on Proposition 1-2-3, a binding ballot referendum that would fundamentally change the system by allowing some rent-control tenants to purchase their apartments after living in them for at least two years.

Supports of the measure say it will give thousands of city residents an opportunity to buy homes, which they otherwise could not afford. But 1-2-3 opponents contend that the proposition would cripple the rent control system and dangerously deplete the city's stock of affordable housing.

Heavily backed by Cambridge's real estate industry, the pro-1-2-3 lobby contends that its opponents are insensitive to the needs of low-income city residents.

"I think they're just upset because they haven't done anything to help [those with low incomes]," says Rosemary D. White of the pro-1-2-3 Cambridge Homeownership Association (CHOA).

But 1-2-3 opponents say the referendum is deceptive because it claims to promote affordable housing while actually gutting rent control, its main component.

They say that there are plenty of condominiums available to those tenants who wish to buy one. And they dismiss as "inflammatory" campaign hyperbole White's contention that homeownership is "illegal" in Cambridge.

"People can buy apartments," says Pamela A. Bender of the Committee to Defeat Proposition 1-2-3. "They just can't buy rent-controlled apartments."

And Bender and her cohorts say that approving Proposition 1-2-3 would not even help tenants purchase their apartments. Proponents of the referendum argue that the apartments would be sold perhaps as much as 50 percent below the market price because each apartment would have only one possible buyer. But a stud sponsored this summer by those opposed to Proposition 1-2-3 concluded that significant discounts are unrealistic.

"That was an argument based on rhetoric and not too much else," says Kennedy School student and study author Patrick J. Dober of the discount theory. In fact, Dober found, the average discount 1-2-3 would give tenants is a mere 8 percent.

Dober based his study on the premise that the first part of 1-2-3 would place tenants in a position similar to that of tenants who lived in rentcontrolled apartments before the city's Removal Permit Ordinance of 1979.

By examining the purchase price paid by pre-1979 tenants for their apartments and comparing it to the estimated market price, Dober came up with the 8 percent figure.

But Cambridge realtor Fredrick R. Meyer--Proposition 1-2-3's author--argues that the 50 percent figure is an accurate one. He says Dober's study has a false premise , adding that the Kennedy School student calculated figures in an unorthodox way, resulting in misleading statistics.

And while Dober admits that his study may contain some flaws, he defends his methodology and calls the study the only available empirical data on 1-2-3's effects.

"My whole angle on this is that there's been a lot of rhetoric, but this is the only study that's based on actual data of what the market would be," Dober says.

'Fig Leaf'

Opponents of 1-2-3 also received a boost this summer when the state Department of Revenue ruled that the third part of the referendum--which establishes an affordable housing trust funded by the increased tax revenue generated by condominium conversion--could not be implemented.

The ruling found that such a fund would have to be approved annually by the City Council.

So, as Councillor and rent control advocate David E. Sullivan puts it, "Point 3 is essentially a dead letter. That particular fig leaf that the sponsors are using to cover up the other things they are doing is no longer available."

But Meyer insists that there is nothing wrong with the intent of the third point in its original form, even if it is unworkable.

"When 1-2-3 passes, I dare any one of [the city councillors] to say, 'No, no. no. We don't want the affordable housing fund," he says.

Procedural Limbo

There is also a slim possibility that the referendum may not appear on the November ballot: The city election commission has been wrangling over the wording of the proposition's preamble.

At issue is a preamble reference to "changing rent control. "But since rent control was enacted by a state home-rule petition, a city referendum like 1-2-3 cannot represent an actual "change," sponsors argue.

At a June 6 meeting, the four-member commission approved a compromise wording for the measure. But at a later meeting in August, Republican Commissioner Artis B. Spear, who had originally voted for the compromise, moved to reconsider the decision.

Catching the Voter's Attention

Edward J. Samp, the Republican who chairs the four-member Election Commission, says he opposed the wording at the July meeting because he believed it would mislead voters.

"[The words] were purposefully designed to catch the attention of the person who has come to vote and who has not studied the proposal carefully," says Samp. "The basic argument between [Democratic Commissioner Sondra B.] Scheir and myself is, 'does this in fact constitute a buzzword?'"

City Solicitor Russell B. Higley is now looking into the matter at Scheir's request, and if he decides that Samp was out of order in allowing the August motion, the earlier version will appear on the ballot. Otherwise, the commission may not be able to agree on the wording in time for the election.

"Once that ruling is delivered," says Scheir, "it may very well end up in court anyway."