Unionized maintenance workers at UBC鈥檚 main Vancouver campus are threatening to walk off the job if a contract dispute is not resolved.

The International Union of Operating Engineers says 100 of its members who work on the heating and cooling systems at the university鈥檚 Point Grey campus have voted unanimously in favour of job action.

Union local business manager Adrian David says the workers have been without a contract for three years and are upset they could lose retroactive pay of about $2,500 per member if they reject what the union says are concession demands.

University officials have already said they don鈥檛 believe classes will be affected if picket lines appear.

The union must issue 72-hour notice before job action can begin and the university says it could also seek an essential service designation from the Labour Relations Board of B.C.

David says members of the operating engineers don鈥檛 want to disrupt classes but patience is wearing thin.

鈥淲e hope UBC negotiators will return to the bargaining table quickly to reach an agreement without unfair concessions, otherwise we will regrettably be forced to take limited job action in the near future and escalate until we reach a new contract,鈥� he says in a news release.

The union says it will accept government public sector wage guidelines of a 5.5 per cent increase over five years but David says UBC is seeking concessions on work scheduling in exchange for the pay increase.

The Canadian Press