CRANSTON — After watching a tentative contract go down to defeat, the police officers union is taking its case to a new venue that could ultimately cost taxpayers far more — binding arbitration.

The union move follows a 6-to-3 City Council vote on Monday to reject a contract that would have saved $1.39 million over three years and preserved the jobs of 11 police officers who now face layoffs.

Council members who opposed the deal, negotiated by Mayor Alan W. Fung, said it saved money mostly by leaving positions unfilled. They also said it gave away management rights, codifying an organizational structure that should be decided by higher-ups.

“The council, as a whole, felt that it was a break-even contract,” council President John E. Lanni Jr. said Tuesday. “In other words, yes, we were getting short-term gains, but in the long run we were giving them all back.”

But Fung and union leaders charged that the council members who opposed the deal were playing partisan politics.

Fung called the vote a “disservice to taxpayers.” Sgt. Stephen J. Antonucci, president of Local 301, International Brotherhood of Police Officers, said it appeared that some council members “never had any intention of approving any agreement.”

“We negotiated in good faith … We gave true concessions,” Antonucci said. “My feeling is that they are playing political games.”

Without the new contract, the Republican mayor said the city will have to lay off 11 officers to approximate the savings the contract would have provided. He also said the city will face legal costs in arbitration and could wind up with a less favorable settlement.

Not everyone on the all-Democrat council was happy with the outcome.

Councilman Mario Aceto, who supported the deal along with Paul H. Archetto and Robert Pelletier, said he tried to set up meetings with council members, the mayor and union, only to have council members not show.

“There isn’t anything in this that couldn’t have been worked out,” he said.

Lanni said he hoped the union would continue negotiating, but Antonucci said the council has made it clear there is no point. He noted changes that were presented to council members on Monday, ultimately coming to nothing when the council voted.

According to Fung, the contract, covering about 150 police officers, would have provided some $400,000 in savings during the fiscal year that ends June 30 and a total of $1.39 million in savings over three years. The money-saving measures included raising employee health-insurance costs, eliminating three paid holidays and eliminating clothing allowances for the rest of this year and all of next year.

The contract, retroactive to July 1, 2008, provided no raises — apart from longevity increases — until January 2010, when officers would have received a 1.5 percent raise. They would also receive a 2.95 percent raise at the start of year three.

The contract would have raised officers’ contributions for health insurance, in the case of a family plan, from $1,300 to $1,560 a year. Warwick officers, by comparison, are paying $1,456, according to Fung’s figures. The contribution would have risen again in July 2010 and reached $2,080 when the contract expires on June 30, 2011.

The contract also mentioned health-insurance companies by name, something that council members questioned Monday, and it outlined an organizational structure that, among other things, would allow more officers to work in community policing and deal with gangs.

Council members objected, saying the contract would give away management rights, but Fung defended the move, saying the changes would improve public safety.

Antonucci also defended the moves and said such language is not unusual in contracts.

“Maybe they did give up some management rights, but you know what, they had to give up something in order for us to give up something financially,” he said.

redgar@projo.com