Canadian election campaign limits government as more tariffs loom

OTTAWA (Reuters) - Canadian Prime Minister Mark Carney's decision to call for a snap election for April 28 could curtail his ability to respond forcefully if the United States carries out a threat to impose additional tariffs.

Now that campaigning has started, the government is bound by a so-called caretaker convention, which means it can engage in routine business but should avoid major policy decisions.

The election comes at a particularly sensitive time for Canada given the threat it faces from U.S. President Donald Trump's tariffs and remarks about annexing Canada, which Carney on Sunday called "the most significant crisis of our lifetimes."

Ministers retain their jobs but virtually all aides were obliged to stop using their work emails and cell phones the second the election was announced on Sunday.

This begs the question of what happens if Trump follows through with a plan to slap additional tariffs on Canadian imports on April 2, on top of the 25% tariffs already imposed in March on Canadian imports of steel and aluminum.

The caretaker convention allows the government to take care of urgent business, so Canada would be able to announce the countermeasures it has already promised, experts said, though additional retaliation could be more difficult.

Asked by CBC news on Wednesday whether Canada could impose already announced counter measures during an election, Foreign Minister Melanie Joly replied: "Yes, of course, because ultimately we are the government ... our job is to defend the national interest."

However, talking to Trump, going to Washington or announcing new measures to counter U.S. tariffs, could open Carney to attacks from opposition parties unhappy that he was using his office to bolster his own standing during the campaign.

"I anticipate that during the actual election, people will be a bit more circumspect, but it does depend quite significantly on the will of political actors to restrain themselves," said Philippe Lagasse, a professor and constitutional expert at Ottawa's Carleton University.

Asked on Sunday why he was calling an election in the middle of a tariff war, Carney said he needed a vote to take place to show he has a strong mandate to manage Canada's economy and negotiate with Trump.

During a campaign in October 2015, then Conservative Prime Minister Stephen Harper called a press conference to announce Canada had joined a transpacific trade pact.

Opposition leader Thomas Mulcair complained about the event with reporters, saying "it's inconceivable that Stephen Harper signed a secret deal in the midst of an election campaign." Harper lost the election.

During an election campaign in February in the Canadian province of Ontario, premier Doug Ford came under fire for traveling to Washington to campaign against tariffs. But Ford won reelection.

"The trick is not to be seen as taking advantage of the situation in a way that people are going to think is unfair," said Andrew McDougall, an assistant professor of political science at the University of Toronto

"(Carney) is going to have to be aware that ... that he is technically sort of bound by this convention, and so he doesn't want to be seen to be violating it."

In polls conducted just before the campaign started, the Liberals and official opposition Conservatives were effectively tied.

The results indicate the Liberals would win the most seats, and potentially form a majority government, since their support is concentrated in the eastern half of the country where there are more seats up for grabs.

The Conservatives did not respond to a question on whether they were worried the Liberals might breach the caretaker convention.

(Reporting by David Ljunggren, editing by Caroline Stauffer and Deepa Babington)