Mark Carney, Canada’s new prime minister, doesn’t look like a liberal firebrand.

With his sharp suits and steel-grey hair, the former Goldman Sachs banker has spent years cultivating the image of a centrist technocrat, with a fondness for fiscal discipline and a distaste for political showmanship.

Once, when asked about running for office, he retorted: “Why don’t I become a circus clown?”

But since Donald Trump started imposing tariffs on Canada and absorbing its neighbour as the “51st state”, Mr Carney has reinvented himself, regularly baiting and ridiculing the most powerful man in the world.

It took a trade war and the threat of annexation for the 59-year-old, once seen as just a steady steward of national finances, to come out of his shell.

After 13 years with Goldman Sachs in the world’s banking capitals – London, New York, Tokyo – Mr Carney guided Canada’s central bank through the Great Recession before being headhunted as Bank of England governor in 2013.

Critics saw the Canadian as the voice of Treasury orthodoxy and he aroused the fury from Brexiteers when he declared in 2016 that a vote to leave the European Union would cause a recession.

Jacob Rees-Mogg, the Conservative MP, labelled Mr Carney the “high priest of project fear”.

Carney and his liberals have spotted an opportunity

He survived the outcry and left the bank in 2020, laying the groundwork to assume leadership of Canada’s beleaguered Liberals, despite never having sat as an MP in the House of Commons.

For a long time, that looked like a poisoned chalice, with the party destined for certain defeat at the hands of Conservative leader Pierre Poilievre.

But Mr Carney and his fellow liberals appear to have spied an opportunity in Mr Trump’s increasingly aggressive rhetoric to make headway against the political Right.

Now, the 59-year-old has emerged as a forthright defender of Canada and arch Trump critic, while Mr Poiliviere has frantically backpedalled away from the US president.

In one of Mr Carney’s most colourful attacks, he compared Mr Trump to the reviled Harry Potter villain Lord Voldemort for his repeated calls to annex Canada.

He said: “When you think about what’s at stake in these ridiculous, insulting comments of the president, of what we could be, I view this as the sort of Voldemort of comment.”

And when Mr Trump imposed 25 per cent tariffs on Canada last month, the former Bank of England governor labelled the move “illegal” and vowed not to “bow down to a bully”.

“In the trade war – just like in hockey – we will win,” he added, referring to a Four Nations final between the US and Canada last month. It allowed Mr Carney to talk about a sport close to his heart, having played for both Harvard and Oxford as a student.

Going viral with Jon Stewart

In January, he earned laughs and viral attention on the US’ Daily Show as he compared the US and Canada to a couple going through a break-up, with interviewer Jon Stewart playing the part of a spurned lover.

“We’re resetting the relationship – we’re going to be stronger moving forward,” Mr Carney said, straight-faced, saying the two countries could be “friends with benefits”.

“It’s not you, it’s us,” he added.

Mr Stewart assured him: “We won’t levy tariffs on all your goods as retribution for your not going out with us. We respect your boundaries.”