By Pras Rajagopalan

The province's largest trade union has endorsed Joe Pantalone for mayor, while another union is throwing its support behind rival George Smitherman six days ahead of the municipal election.

The Canadian Union of Public Employees Ontario told almost 100,000 Toronto members on Tuesday to back Pantalone.

"Joe Pantalone is the most committed to public services, has the most experience at getting city council to work together and will not sell off public assets," Fred Hahn, the union's president, said in a news release.

Smitherman has said he is open to the idea of contracting out some city services, including waste management, something Pantalone has said he will not do.

Recent polls have suggested that Rob Ford and Smitherman are the frontrunners in the race, with Pantalone lagging significantly behind. Ford has said he would contract out city services and would scrap Toronto's fair wage policy, which requires contractors working for the city to pay union rates to workers.

Smitherman has increasingly positioned himself as the only viable alternative to Ford, saying a vote for Pantalone is a vote for Ford.

But Hahn rejected the idea of strategic voting, saying the undecided vote is "starting to shift" and "there is no reason why we can't have the best for our city, and the best mayor will be Joe Pantalone."

Meanwhile, the Central Ontario Building Trades, which represents about 60,000 construction workers in Toronto, is telling its members to support Smitherman.

The group backed outgoing Mayor David Miller - who in turn has endorsed Pantalone -- in the last two municipal elections.