Foreign Secretary Liz Truss has set a 48-hour deadline for a fishing dispute with France to be resolved before the UK moves ahead with legal action.

Speaking to Sky News at the COP26 climate change summit in Glasgow, Ms Truss hit out at the French for behaving “unfairly” and accused them of operating outside the terms of the Brexit trade deal.

Last week, French authorities detained a British scallop trawler in the port of Le Havre as fresh tensions over post-Brexit fishing rights broke out.

The dispute revived a French threat to raise the price of electricity supplied to Jersey, in the Channel Islands, via underseas cables.

“The French have made completely unreasonable threats, including to the Channel Islands and our fishing industry, and they need to withdraw those threats,” Ms Truss said.

“Or else we will use the mechanisms of our trade agreement with the EU to take action.

“What that means is that we will use the dispute resolution mechanism, which could lead to taking direct action in trade.”

The foreign secretary added: “The French have behaved unfairly, it’s not within the terms of the trade deal.

“And if somebody behaves unfairly in a trade deal, you are entitled to take action against them and seek some compensatory measures.

“That is what we will do if the French don’t back down.”

Ms Truss said the issue “needs to be resolved within the next 48 hours” before the UK moves ahead with legal action.