METHUEN — Police officers are fighting the city to get paid for Christmas Eve and New Year's Eve, arguing that they should earn holiday pay for those days because the mayor gave City Hall workers those days off.

Mayor William Manzi refused the request of the patrolmen's union, saying the city can't afford it and it is not in the police contract. The union appealed the decision, and now the grievance will be heard at an arbitration hearing.

The 65-member patrolmen's union argued that officers should be paid for eight hours of contractual time off for Christmas Eve and 31/2 hours for New Year's Eve, according to a memo from the union to the city.

The Methuen Police Patrolmen's Association president, Officer Joseph Aiello, referred questions to the union's representatives at the Massachusetts COPS Coalition because they are handling the arbitration filing.

"The MPPA deems this time off to be an unfair labor practice for failing to negotiate in good faith additional benefits to certain employees and unions and omitting the same benefit to members of the MPPA," the union writes in its appeal.

The union also argues that it is "past practice" for 14 years for union members to receive contractual pay for these two days. A lawyer for the Mass COPS Coalition did not return a call Friday.

"Certain collective bargaining units have that holiday and (patrolmen) don't," Manzi said. "It's a matter of the city not being able to afford to grant (paid time off) beyond the benefits of the existing contract."

City Hall secretaries, clerks and administrative assistants received that time off because it is stipulated in their contracts, said Human Resources Director Colleen McCarthy. Civilian police employees, including department secretaries, enjoyed the extra holidays because they are also part of the American Federation of State, County and Municipal Employees.

Some nonunion City Hall employees and department heads were granted that time off by the mayor because City Hall was closed Christmas Eve and closed early New Year's Eve.

"With all the support personnel gone, I did give a couple of administrative personnel time off because they would have had no one in their office," Manzi said.

Manzi said union negotiations led to different benefits.

"It's the way negotiations go," Manzi said. "The contract we reached with them was eminently fair. I don't think there's any hardship in the contract. It treats them quite well."

Police officers signed a new three-year contract with the city last year that is retroactive to 2006. Under the contract, officers received 2 percent raises retroactive to July 1, 2006; 3 percent in 2007, and 3 percent in 2008.

Manzi said the additional holiday pay would be a "sizable chunk" of money, but he could not provide specifics.

"Cities and towns are going to be seeking a lot more (from unions) in future contracts," Manzi said. "Even in areas where we've been justifiably generous in the past, city and towns can't afford this now. Taxpayers can't afford it."