San Francisco's police officers union overwhelmingly accepted a deal Saturday that will allow them to receive past raises owed to them and avoid layoffs for at least a year while agreeing to pay more into their pension fund at an earlier date.

The deal, forged by San Francisco Mayor Ed Lee and the union, will help to balance the city's $6.8 billion budget. But it is likely to further fuel the ongoing battle over public worker pensions, which may culminate with dueling reform measures on November's ballot.

Public Defender Jeff Adachi, who hopes to qualify a competing measure for the November ballot, has called Lee's deal a gimmick.

Police officers, due 5 percent in raises before the fiscal year is over, will get a 3 percent raise immediately and the remaining 2 percent in April.

They agreed to pay an additional 3 percent to their pension fund for two years - two years earlier than would be required if the mayor's pension reform proposal passes in November.

In agreeing to extend their contract until 2015, two years past its expiration date, San Francisco Police Officers Association leader Gary Delagnes said Saturday that the officers received an assurance that none would be laid off through the current fiscal year.

The membership approved the deal by a vote of 1,126 to 258, he said.

"I'm grateful to the membership, because it was the right thing to do," Delagnes said. "They recognize the economic situation we are in, and responded."

Said Lee Saturday: "I am very grateful for the sacrifice made and for the rank and file's help in balancing the budget, saving jobs and keeping the city safe."

Adachi had been critical of the deal.

Last week he said, "To simply say, 'Well, we're going to require employees to contribute more toward their pensions,' and then turn around and give a raise that pays the pension increase is not good policy, and it's a bad political deal for taxpayers."

Should the city's firefighters union accept a similar deal, the plan will save taxpayers $31 million over the next two years, the mayor's office said. Firefighters are expected to vote in the next few days.

Delagnes hoped the firefighters will accept their deal.

"In the court of public opinion, to have cops on one page and firefighters on another would not be a good message to send," he said.