The City of Winnipeg's largest labour union is hinting at the potential for a work stoppage in advance of a final offer from the city expected early next week.

The Canadian Union of Public Employees Local 500, which represents 5,070 city workers, has been without a contract since Dec. 24. Contract talks with the city have been strained, with both sides accusing the other of engaging in unfair labour practices.

The city plans to present a final offer to the union on Tuesday, CUPE 500 president Gord Delbridge said.

"They're asking for a lot of concessions," he said in a telephone interview, declining to reveal specifics of the offer he expects to see after the long weekend. "It will be difficult to have it ratified."

Delbridge also said the city has not accepted any of the union's proposals.

In a notice to its members posted on Thursday afternoon, the CUPE 500 negotiating team suggested its members ought to be wary of their personal financial situations.

"Our goal remains to reach a fair and reasonable collective agreement that meets the priorities of our members. The Union's negotiating committee is doing our utmost to settle this round of bargaining without resorting to any job action," said the notice.

"Until such time as we have had a chance to review the offer of settlement, you may want to be attentive to any discretionary spending."

Unlike unions representing city police and firefighters, CUPE 500 has the right to strike. Its members work in a wide variety of roles for the city in many departments.

City of Winnipeg communications director Felicia Wiltshire said in a statement the city won't negotiate through the media and will not discuss the offer or the potential for an impasse.

"The city recognizes the important work performed by all of our staff in CUPE, and remains committed to finding a fair and reasonable solution to these negotiations," she said in a statement.

"We are looking to come to an agreement that is fair and reasonable to all parties, including Winnipeg taxpayers."