Conservative MP Johnny Mercer says he has withdrawn his support for the government over the historical prosecution of British servicemen.

A former Army officer, Mr Mercer called on Theresa May in a letter to end the “macabre spectacle of elderly veterans being dragged back to Northern Ireland” to face possible prosecution.

In his letter to the prime minister, the Plymouth Moor View MP said he found investigations into historic allegations surrounding ex-services personnel “personally offensive”

He said he was not to prepared to vote for Government legislation - except on Brexit - until the Government took “clear and concrete steps” to end the “abhorrent process”.

“As you know, the historical prosecution of our servicemen and women is a matter that is personally offensive to me. Many are my friends; and I am from their tribe,” he wrote.

Remembering The Troubles in pictures Show all 15 1 /15 Remembering The Troubles in pictures Remembering The Troubles in pictures A British soldier attacks a protester in Derry on Bloody Sunday Getty Remembering The Troubles in pictures The Northern Ireland Civil Rights movement marches in London in 1968 to demand the same voting rights afforded to the rest of Britain Getty Remembering The Troubles in pictures The Northern Ireland Civil Rights Association marching on the streets of Derry in 1968 BBC Remembering The Troubles in pictures The Battle of the Bogside in Derry in August 1969 was among the first violent episodes of the Troubles The Battle of the Bogside in Derry in August 1969 was among the first violent episodes of the Troubles Getty Remembering The Troubles in pictures British soldiers take cover behind their armoured cars as they use CS gas to disperse rioters in Derry on Bloody Sunday PA Remembering The Troubles in pictures Hugh Gilmore (third left) clutches his stomach after being shot by a British soldier on Bloody Sunday. Gilmore was one of 14 to be shot dead on 30 January 1972 PA Remembering The Troubles in pictures A man receives attention after being shot on Bloody Sunday in Derry PA Remembering The Troubles in pictures A young man is led away by paramedics after being injured on Bloody Sunday PA Remembering The Troubles in pictures The British Embassy at Merrion Square in Dublin is bombed following a march to protest three days after the Bloody Sunday shootings Getty Remembering The Troubles in pictures Independent MO for Mid-Ulster Bernadette Devlin talks to the press after she hit Home Secretary Reginald Maudling for lying about the Bloody Sunday shootings in his statement to the House of Commons the day after the incident. Devlin had been in Derry at the time of the shootings and was moved to strike the Home Secretary after he claimed that British soldiers had only fired at protesters in defence Getty Remembering The Troubles in pictures Members of a Catholic community in Newry stage a protest against the Bloody Sunday shootings AFP/Getty Remembering The Troubles in pictures Relatives mourn over the coffin of a victim of Bloody Sunday on 1 April 1972 Getty Remembering The Troubles in pictures Thousands attend the annual Bloody Sunday memorial march in Derry on 30 January 1995 PA Remembering The Troubles in pictures UK prime minister Tony Blair and the Irish taoiseach Bertie Ahern sign the Good Friday Agreement in 1998 PA Remembering The Troubles in pictures A view over residential Derry in 2019 shows a mural on Rossville Street, where soldiers opened fire on Bloody Sunday Getty

“These repeated investigations with no new evidence, the macabre spectacle of elderly veterans being dragged back to Northern Ireland to face those who seek to re-fight that conflict through other means, without any protection from the Government who sent them almost 50 years ago, is too much.

“I will not be voting for any of the government’s legislative actions outside of Brexit until legislation is brought forward to protect veterans from being repeatedly prosecuted for historical allegations.”

Mr Mercer has campaigned against the pursuit of legacy cases from the conflicts in Northern Ireland, Afghanistan and Iraq since he entered Parliament in 2015.

In March, the Public Prosecution Service (PPS) of Northern Ireland announced one former British solider would face two murder charges over the Bloody Sunday shooting in Derry in 1972.

A total of 13 people were killed in the incident after British paratroopers opened fire on what was classed as an illegal civil rights march through the Bogside area of the city.

However, relatives of those who died have expressed disappointment that only one of the paratroopers, referred to only as Soldier F, will face trial.

Mr Mercer’s intervention will be seen in Westminster as further evidence of the prime minister’s crumbling authority.

He recently accused the Tory whips office of contacting former Army comrades in an attempt to dig up dirt on him.

Support free-thinking journalism and attend Independent events

He wrote in his letter: “It has not been an easy decision to make. But this incident with your chief whip has forced my hand.

“It appears that my values and ethos may be slowly, but very firmly, separating from a party I joined in 2015.”

There was no immediate response from Downing Street to his letter.