TORONTO (AP) – The Liberals are set to join the New Democratic Party in voting against a softwood lumber deal with the United States.

The agreement has support of elected officials in Maine and elsewhere who say it would moderate an edge Canadians enjoy from subsidies their government provides. Canada accounts for about a third of the American market for softwood, the pine, spruce and other wood used in homebuilding.

Last week, U.S. Sen. Olympia Snowe, R-Maine, said the compromise would “bring an end to decades of litigation over the unfair subsidizing of the Canadian lumber industry by the government.”

The Liberal Party’s position is the toughest line it’s taken on the softwood agreement, which Prime Minister Stephen Harper said he would put to a confidence vote when the Commons returns Sept. 18.

Ralph Goodale, the Liberals’ House leader, told the Toronto Star he’s seen nothing that would persuade him to support the deal and signaled his party would be willing to trigger an election. But that outcome doesn’t seem likely.

Bloc Quebecois Leader Gilles Duceppe hasn’t said whether his party would prop up the Tory government in the vote, but he’s consulting with industrial producers in Quebec, who overwhelmingly support the deal.

A government source told the Toronto Star that Quebec industry supported the deal 157-3, making it unlikely the Bloc will vote it down and topple the Harper government.

After Harper announced last week he had a “clear majority” of support from the big lumber producing provinces and industry players, interim Liberal leader Bill Graham said he party wanted to consult the forestry industry and study the deal before stating its position.

But Wednesday, Goodale took a more firm approach, saying his party is prepared to risk triggering an election if the Bloc also votes against the deal.

“If that’s what eventually happens because of this, then I think the party’s prepared to grapple with that consequence,” he said.

With Bloc support the Tories will easily defeat the Liberals and NDP.

The Conservatives hold 125 of the 308 Commons seats. The Liberals hold 102, the Bloc 50 and the NDP 29.

Under the deal, the United States would pay back about $4 billion of $5 billion (U.S.) in punitive duties paid by Canadian lumber producers. It has been endorsed by the premiers of the three big softwood producing provinces: British Columbia, Ontario and Quebec.

The Liberals object to the deal on several fronts, including that it undermines the North American Free Trade Agreement and that it fails to return $1 billion in duties.