The City of Winnipeg's largest union has voted to give its leaders a strike mandate.

Members of the Canadian Union of Public Employees Local 500, which represents more than 5,000 city workers, voted 85 per cent to reject a city contract offer that called for a wage freeze this year, modest increases later and what the union characterized as widespread concessions.

Union president Gord Delbridge said membership turnout was approximately 80 per cent, a turnout he described as significant.

Delbridge said while 50 of his members have already signed up to be strike captains, he remains committed to attempting to negotiate a settlement with the city.

"Today's strike mandate does not necessarily mean we're going on strike. Today's strike mandate means a majority of workers do not consider the city's offer acceptable," Delbridge said.

"I think the city needs to realize that what we're asking for is just to get a fair and reasonable offer. We're proud of the services that we provide to the citizens of Winnipeg. There's a lot that's going to be going on this summer and we want to be there to provide those services.

"We're proud of the work that we do. We know we do good work. We hope the city comes back and treats us with some respect."

A union representing general Winnipeg municipal workers has not gone on strike since a CUPE 500 predecessor union took part in the Winnipeg General Strike of 1919, Delbridge said.

A strike mandate usually results in more negotiations, said University of Manitoba labour studies co-ordinator Julie Guard.

"It shows the employer that the members of the union are really serious about the proposals, that they care enough about them that they are prepared to go on strike, should they not get an agreement that works for them," Guard said in an interview.

"It is not uncommon for the discussions to continue," said Mayor Brian Bowman earlier in the day, insisting the city is eager to reach a deal through a negotiated settlement with CUPE 500. "We respect their ability work through the process that they're following right now."

Brian Bowman

Mayor Brian Bowman said he's hopeful for a negotiated settlement with the city's largest union, even if CUPE 500 leaders receive a strike mandate tonight. (Tyson Koschik/CBC)

In a statement, Winnipeg chief corporate services officer Michael Jack reassured citizens that in the event of a work stoppage, the city will continue to provide essential services such as drinking water, policing, firefighting and paramedic response.

"City services that are contracted out, such as recycling and garbage pickup, would continue in a work stoppage, as would Winnipeg Transit," he said.

"Many non-essential services would either be reduced or closed temporarily. With regard to all other services the City of Winnipeg offers, the public would be informed with a comprehensive list of which services would or would not be provided, in the event of a work stoppage."