The fate of the North American free trade deal now rests in Canadian hands, but approval of the pact is uncertain at best as the country remains seriously split over the issue.

President Reagan on Wednesday signed the sweeping deal that proposes to tear down remaining barriers between the hemisphere's two largest trading partners.U.S. legislation implementing the deal with Canada sailed through Congress with only limited opposition.

But in Canada the deal has received a rocky reception since Conservative Prime Minister Brian Mulroney signed the initial treaty with President Reagan in January.

Canada's two opposition parties, perhaps playing to the assortment of groups opposing the agreement, have launched strong campaigns to block passage of the required legislation.

Opposition Liberal Leader John Turner stunned the country with the announcement the party would use its majority in the unelected Senate to block the pact until an election is called on the issue.

The legislation has been passed by the elected House of Commons where the Conservatives hold a majority.

Mulroney has called Turner's move an outrage and has boasted he would love to fight an election on the issue. An election is widely expected to be called in the next few days for a late November vote.

Turner, meanwhile, remains undaunted in his battle to block the deal.

"And, as I have clearly said before and will repeat throughout this campaign, we will say `No' to Brian Mulroney's sell-out trade deal," Turner told a news conference on Wednesday.

Political analysts believe the trade agreement will be front and center in the coming campaign and will probably intensify the already searing national debate over the issue.

In contrast to the United States, where the pact has received scant media attention, the trade story is constantly in the headlines.