Thousands of Australian firefighters will boycott the annual World Police and Fire Games in Montreal next year due to an ongoing dispute between the city and its firefighters over pension reform.

Montreal firefighters are also boycotting the games and their union has appealed to their international colleagues to do the same.

On Thursday, the union issued a news release stating its appeal was heard by 6,200 firefighters in New South Wales, who have vowed to boycott the games. 

The Fire Brigade Employees' Union in Sidney, Australia, and the Fire and Rescue New South Wales Sports Association, are also in favour of the boycott, the union says.

"This major international support shows the extent to which the unfair treatment of municipal employees — and firefighters in particular — is helping tarnish the image of the Quebec government and the City of Montreal even at the other end of the planet," said union president Ronald Martin.

Union spokesman Chris Ross told CBC Montreal Thursday that Montreal firefighters would be happy to see the games cancelled.

"We don't believe Montreal warrants holding the games, so if the games were cancelled completely, we certainly wouldn't have a problem with that," he said.

"Whether the games are held or not, it's certainly not something that interests us," he said.

Originally, around 12,000 firefighters from 70 different countries were expected at the games, but the union says it expects only a few thousand will come.

Montreal firefighters are protesting changes to their pension that became law in 2014. The law forces municipal workers to pay more into their pensions.