Metro Vancouver's 200 Transit Police officers say they have been without a contract since 2011 and now they want a retroactive pay increase.

David Black, the president of COPE 378, says the union is trying to negotiate a six per cent increase for the next two years and a retroactive raise of five and a half per cent dating back to 2011.

Black says the money would help keep members' pay in line with other police departments

"What our folks at transit police are looking for is just looking to keep up with inflation and looking to keep up with other police departments. Our agreement expired a number of years ago," he said.

But critics of the request, such as Jordan Bateman with the Canadian Taxpayers Federation, say Transit Police already have it good, especially while funding for future TransLink projects is uncertain.

"Transit Police actually get a far better deal that a lot of police forces. For example transit cops get a 25 per cent bonus for working Sundays. No other police force gets that," says Bateman.

He also says the combined wage increase of 5.5 per cent and six per cent over four years would outpace inflation.

"The cost of living has actually flat-lined in Greater Vancouver," Bateman notes.

Negotiations between the union and TransLink are still underway.

With files from the CBC's Meera Bains