The “last-minute changes in the US terms were unfair, uneconomic, and called into question the reliability of any deal”, said Carney. Trade negotiators had been engaged in intense talks since July, after President Donald Trump threatened to impose a 50 per cent levy on nearly $20bn (C$28bn; £14bn) of Canadian imports by 19 August. Trump had temporarily suspended the tariffs earlier this week, saying the two sides were close to signing a trade deal that was “very good” for both countries.

But minutes before the deadline for a deal, Carney said that while “important progress” had been made in the talks it was “not enough to meet our objectives for Canadians”. After Carney’s announcement US trade representative Jamieson Greer said in a statement: “Tonight, Canada declined to finalise the trade deal under the terms agreed earlier this week. Despite the US offer to Canada to receive the best treatment of any major exporter to our market, new demands and walk backs of other commitments by Canada have upended the careful balance reached in the past days.”

Negotiators were reportedly discussing a deal that would reduce US tariffs on Canadian steel and aluminium from 50 to 25 per cent, and on Canadian autos from 25 to 15 per cent. In exchange, Carney had asked Canadian provinces to restore US alcohol to store shelves. While Canada sends approximately 70 p.c. of its exports to the US, tension between the two trading partners have been simmering since Trump returned to office in January last year and unleashed a wide-ranging global programme of tariffs, upending decades of free trade between Canada and the US.

Now that talks have broken down, Canada will be hit with new 50 per cent US tariffs imposed by Trump using a Depression-era law called the Tariff Act of 1930. They will be applied on a range of goods including wine, dairy, cement and clothing. The new levies are in addition to existing tariffs the US had already imposed on Canadian steel and aluminium, autos and lumber.