TORONTO (AP) -- Canadian Prime Minister Mark Carney is expected to trigger the process for an early parliamentary election this weekend for an expected vote on April 28.

The election will take place against the backdrop of a trade war and sovereignty threats from U.S. President Donald Trump.

The governing Liberals had appeared poised for a historic election defeat this year until Trump declared a trade war. Trump has repeatedly said that Canada should become the 51st U.S. state and he acknowledged Friday that he has totally upended Canadian politics.

What Trump hasn't said is that the almost daily attacks on Canada's sovereignty have infuriated Canadians, who are canceling trips south of the border and avoiding buying American goods when they can. The surge in Canadian nationalism has bolstered Liberal poll numbers.

The opposition Conservatives hoped to make the election about former Prime Minister Justin Trudeau, whose popularity declined as food and housing prices rose and immigration surged. But after decades of bilateral stability, the vote is now expected to focus on who is best equipped to deal with the United States.

Carney will visit Governor-General Mary Simon on Sunday and request to dissolve Parliament, a government official who wasn't authorized to publicly give details so spoke on condition of anonymity on Thursday.

Requests by the prime minister to the governor-general are rubber-stamped. Simon's office holds a constitutional and ceremonial role as the representative of Canada's head of state, U.K. King Charles III. Canada is a member of the British Commonwealth of former colonies.

An election campaign lasting about five weeks will then officially begin.

People throughout Canada will elect all 338 member of the House of Commons, one for each constituency. There are no primaries or runoffs, just a single round of voting.

Canada is like Britain in that uses a "first past the post" system of voting, which means that the candidate that finishes top in each constituency will be elected, even if they don't get 50% of the vote.

This has generally cemented the dominance of the two largest parties, the Liberals and Conservatives, because it's difficult for smaller parties to win seats unless they have concentrated support in particular areas.

The party that commands a majority in the House of Commons, either alone or with the support of another party, will form the next government and its leader will be prime minister.

Carney replaced Trudeau, who announced his resignation in January, but remained in power until the Liberal Party elected a new leader on March 9 following a leadership race by the governing Liberal Party.

He was sworn in as Canada's 24th prime minister on March 14. Carney said Thursday in this time of crisis that the government needs a strong and clear mandate.

Carney, 60, is among the two main candidates. He navigated crises when he was the head of the Bank of Canada and when in 2013 he became the first noncitizen to run the Bank of England since it was founded in 1694.

His appointment won bipartisan praise in the U.K. after Canada recovered from the 2008 financial crisis faster than many other countries.

A highly educated economist with Wall Street experience, Carney worked for 13 years for Goldman Sachs in London, Tokyo, New York and Toronto, before being appointed deputy governor of the Bank of Canada in 2003. He has both financial industry and public service credentials.

Carney still hasn't had a phone call with Trump yet. He has said that he's ready to meet with Trump, if he shows respect for Canadian sovereignty.

Pierre Poilievre, the leader of the Conservatives, is Carney's main challenger. The party and Poilievre were heading for a huge victory in Canada's federal election this year until Trump's near-daily trade and annexation threats derailed them.

Poilievre, 45, for years the party's go-to attack dog, is a career politician and firebrand populist who says he will put "Canada first." He attacks the mainstream media and vows to defund Canada's public broadcaster. His party announced that it won't allow media onboard his campaign buses and planes.

"President Trump's tariffs and his rhetoric about Canada becoming the 51st state have clearly helped the Liberals in the polls while putting the Conservatives in an odd position, as their rhetoric exhibits some similarities with Trump's and a significant minority of their supporters like the President's populist style and ideas," said Daniel Béland, a political science professor at McGill University in Montreal.

Poilievre has said he will stand up to Trump.