Emily Thornberry, Labour’s Shadow Foreign Secretary, responding to reports that Theresa May has refused to sign a joint statement with other European leaders expressing regret at President Trump’s withdrawal from the Paris agreement, said:

“The leaders of France, Germany and Italy are absolutely right to stand by the Paris Agreement and make clear to Donald Trump that it is not up for renegotiation. The commitments made in Paris are vital to stop the world reaching the point of no return on climate change, and there can be no question of watering them down.

"The only question is why Theresa May does not have her name on this joint statement. Given the chance to present a united front with our European partners, she has instead opted for cowardice and subservience to Donald Trump. It is a dereliction of her duty both to our country and to our planet.

"It is bad enough that she failed so badly to persuade Trump to stick to the Paris agreement, but it is even worse that she lacks the backbone to stand up to him now. This proves that Mrs May is the very last person we want negotiating for Britain on Brexit.”