THERESA May is to offer British troops protection against vexatious legal claims arising from future conflicts by introducing an automatic opt-out from certain aspects of human rights law.

Under changes being announced at the Conservative conference in Birmingham today, the UK Government will adopt a presumption that it will "derogate" from the European Convention on Human Rights at times of war.

The Prime Minister said the move should end an "industry of vexatious claims," which has seen veterans of Iraq and Afghanistan pursued through the courts over alleged mistreatment of combatants and prisoners over a decade after the supposed events took place.

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And she said it would reduce the burden on taxpayers, which has seen the Ministry of Defence spend more than £100 million on Iraq-related investigations, inquiries and compensation since 2004.

Mrs May last month raised concerns over the "industrial scale" of claims lodged with the Iraq Historic Allegations Team[IHAT], which was set up in November 2010 to look into allegations of murder, abuse and torture of Iraqi civilians by UK military personnel between 2003 and 2009.

IHAT has considered claims relating to more than 1,500 individuals, ranging from ill treatment during detention to assault and death by shooting.

Some 326 cases have been settled with the payment of around £20m in compensation but concerns have been raised about servicemen facing investigation even after having been cleared of wrongdoing by criminal courts.

Military advisers have warned that the extension of the convention's provisions to the battlefield threatens to undermine the operational effectiveness of the armed forces, said Government sources.

The 1953 convention permits signatories to suspend their obligation to observe certain human rights responsibilities "in time of war or other public emergency threatening the life of the nation".

But the procedure - known as "derogation" - may not be used in respect of the right to life and prohibitions on torture, slavery and retrospective criminal penalties.

France took advantage of the procedure in November 2015 during its response to the terror attacks in Paris, while the UK took the same step several times during the Northern Irish Troubles in the 1970s, and was backed by the European Court of Human Rights.

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The PM said: "Our armed forces are the best in the world and the men and women who serve make huge sacrifices to keep us safe.

"My Government will ensure that our troops are recognised for the incredible job they do. Those who serve on the frontline will have our support when they come home.

"We will repay them with gratitude and put an end to the industry of vexatious claims that has pursued those who served in previous conflicts.

"Combined with the biggest defence budget in Europe, the action we are laying out today means we will continue to play our part on the world stage, protecting UK interests across the globe," added Mrs May.

The announcement follows the closure in August of law firm Public Interest Lawyers, which had represented many complainants against the armed forces.

It also comes after the Government said it would create new penalties for firms engaging in "vexatious" practices to drum up cases.

The Conservative manifesto for last year's general election committed the party to ensuring that "British armed forces overseas are not subject to persistent human rights claims that undermine their ability to do their job".

But ministers stressed that UK forces would at all times be required to operate in accordance with international humanitarian law - including the Geneva Conventions - and service law.

Defence Secretary Sir Michael Fallon said: "Our legal system has been abused to level false charges against our troops 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.

"This change is an important step towards putting that right - a key commitment the Conservative Party made in last year's general election.

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"It will help to protect our troops from vexatious claims and ensure they can confidently take difficult decisions on the battlefield. And it will enable us to spend our growing defence budget on equipment, not fees for lawyers."

The Government plans have been welcomed by veterans and their families.

Reg Keys, whose son Tom, 20, was killed while guarding a police station in Iraq in 2003, branded lawyers bringing claims against veterans "ambulance chasers".

Mr Keys and other bereaved parents are leading a campaign against the prosecutions against armed services personnel, which he described as an "abomination".

"I applaud Theresa May for taking this step,” he declared. “It's not for politicians and lawyers to look at the actions of British service personnel in a war zone and the decisions that had to be made.

"They may sit in comfy padded seats in Whitehall pontificating over this - they themselves should try and be in one of those war zones facing the anger and the venom of the enemy.

"The fact that this has now been abandoned makes me breathe a sigh of relief because we ask our troops to do a very difficult job under very difficult circumstances."

Mr Keys added: "These lawyers pushing this are ambulance chasers of the very worst kind.

"These men and women that have gone to these war zones for the sake of their own country are now the very ones being pursued by lawyers in their country.

"It's an abomination and they[the lawyers] should be ashamed of themselves.

"I would like to think that those already under threat of prosecution will be looked at again."

MP Johnny Mercer, a former Army captain who served in Helmand province, also welcomed the decision and said the situation should never have been allowed to happen.

He said: "I'm delighted with the announcement. This is the first step in closing the gap that exists in this country today between politicians and those who serve.

"To continue to try and apply human rights laws in combat represented a fundamental misunderstanding by ministers about what we are asking our people to do to keep us safe."

He added: "This should never have happened in the first place and we need to focus on what we do about those currently having reheated so-called evidence thrown at them for prosecutions by a legal machine that simply exists to make money from the public purse."