Local opponents of Proposition 2 1/2 say they will redouble efforts to defeat the referendum, now that its support appears to be slipping.

A poll in yesterday's Boston Globe shows majority of Bay State voters support the measure, which will slash property taxes in many cities and towns. The predicted margin of victory for the referendum appears smaller, now, however, and many of those questioned said they had yet to decide.

"My feeling is that gap has narrowed," Cambridge Mayor Francis H. Duehay '55, who is leading the local campaign against the measure, said yesterday. "There seems to be some additional awareness about what the law will do if it is passed," he added.

The Cambridge Committee of 350 Against Proposition 2 1/2 will drop leaflets, telephone voters and set up information tables over the next month, he said. "They're still in the lead, though; we have a lot of work to do," Duehay added.

Greg Hyatt, a consultant for Citizens of Limited Taxation--which is sponsoring the referendum, question 2 on the November ballot--said the proposition's support is not eroding. "The scare tactics of the opposition are increasing, that's all," he said.

Hyatt promised that backers of Proposition 2 1/2, including many state business organizations, would gear up for an intensive advertising campaign by the end of the week.

"We don't have as much money as all the public employee's unions and such that are opposing us, but we don't need as much either," Hyatt said. "Fundamentally, the people are on our side," he added.

The amendment would limit local property taxes to 2 1/2 per cent of a community's property values and cut auto excise taxes. Its supporters last week began accusing opponents of using public funds and facilities in their campaign. Hyatt's group charged Cambridge and several other cities with allowing municipal buildings to be used for rallies against the proposition, but added the CLT would probably not go to court.

"These are a lot of little brushfires--we just want to draw people's attention to them," Hyatt said.

Duehay called the charges a "political ploy" and insisted that city money is not financing the opponents.

"The CLT is using it as a tactic to persuade voters that the only people opposed to the proposition are entrenched politicians," he said.