Theresa May has been accused of wanting to cover up war crimes committed by British soldiers by a world-leading human rights lawyer.

In her speech to the Conservative party conference, the Prime Minister pledged to rapturous applause that “we will never again in any future conflict let those activist left-wing human rights lawyers harangue and harass the bravest of the brave, the men and women of our Armed Forces”.

Under Government proposals, British soldiers would be exempt from action under European Court of Human Rights law. However, they would still be subject to International Humanitarian law, including the Geneva conventions and UK criminal law.

Geoffrey Robertson QC, a former United Nations’ appeals judge, wrote in an email to The Independent that Ms May’s rhetoric was becoming "increasingly ignorant".

“Human Rights lawyers are not necessarily either activist or left wing and they do not harass the brave – they call for the prosecutions of those cowardly soldiers who kill their prisoners and torture or murder civilians," he said.

“These actions have been war crimes for centuries and Mrs May, quite disgracefully, wants to cover them up when they are committed – and it is a matter of record that they are occasionally committed – by British forces.”

Mr Robertson added that solicitors who made false claims against soldiers should be quickly and fairly investigated.

“A solicitor who deliberately fabricates a claim deserves to be drummed out of the profession and drummed into jail,” he said.

Theresa May tells public to 'come with me and seize the day'

A Downing Street source said Ms May had "always said it's right to investigate legitimate instances, but it's the industry of vexatious claims that must end".

In a speech to the party conference on Tuesday, Defence Secretary Michael Fallon said the legal system had been abused to bring false charges against soldiers on an "industrial scale".

"It has caused significant distress to people who risked their lives to protect us, it has cost the taxpayer millions and there is a real risk it will stop our armed forces doing their job," he said.

The Government’s plan has been condemned by the father of an army recruit who died at Deepcut Barracks.