MPs, families and legal experts have raised serious concerns about comments made by the defence secretary, Gavin Williamson, suggesting that British troops should break the law by carrying out targeted extrajudicial killings of British jihadists.

The Labour MP and former paratrooper Dan Jarvis said Williamson’s comments that Britons who had fought for Islamic State abroad should be hunted down and killed were “morally, legally and practically wrong” and contravened long-held British policy.

“His statement implies a desire for extrajudicial killing to form part of the UK’s security policy,” Jarvis told the Guardian. “That is so radical a departure from all that we should value, and the way we should conduct ourselves, it is hard even to countenance.

“Such a policy would not only break the Geneva conventions and UK law, but would undermine both our society and the way we defend it.”

Prof Philippe Sands, the internationally renowned barrister, said the comments were inappropriate and Downing Street should confirm British foreign policy had not changed.

Sands told the Guardian: “It sounds as though we have, or are on the cusp of having, on his terms, some sort of shoot-to-kill policy.”

The QC said a policy of targeting and killing British Isis fighters would be “inconsistent with English, European and international law, as well as with United Kingdom foreign and domestic policy for nearly a century since the end of the second world war”.

Sands said the comments were “the words of an inexperienced minister, like someone who has given no thought or reflection at all to the underlying issues”.

“We need a confirmation from No 10 Downing Street that the UK is committed to the totality of its legal obligations in domestic law and international law and it does not operate shoot-to-kill policy in relation to people who violate criminal law.”

Jarvis said Williamson’s comments to the Daily Mail could fundamentally undermine instructions to troops already under intense pressure. “We could no longer turn to our troops and require of them, in often the most difficult of circumstances, to obey the law of armed conflict,” he said.

“We could no longer turn to other nations and ask them to end the extrajudicial killing of their people; and we could no longer turn to the British public and ask them to trust in the rule of law, when we, the lawmakers, are not prepared to do so ourselves.

“The rule of law is key both to the society we are defending and how we defend it. If our response to terrorism is to destroy human rights and the rule of law, the terrorists have won.”

Ken Macdonald, the former director of public prosecutions, told the BBC’s World at One: “It simply will not be lawful in all circumstances to kill jihadis, as the secretary of state seems to be suggesting.”

Williamson, told the Daily Mail: “A dead terrorist can’t cause any harm to Britain.

“I do not believe that any terrorist, whether they come from this country or any other, should ever be allowed back into this country. We should do everything we can do to destroy and eliminate that threat.”

Other politicians condemned Williamson’s comments, as well as John Letts, the father of Briton Jack Letts, who is facing charges from Kurdish authorities of being a member of Isis.

John Letts has claimed UK authorities are unwilling to help him get his son back to Britain, even to face charges in the UK. He said Williamson’s comments were “outrageous … it’s extremist, as far as I am concerned. I don’t think we just assassinate people. We are supposed to have British values – are these British values?

“We are just abandoning a thousand years of Magna Carta and freedom. We are just following the American approach of shoot first, ask questions later, and it is just wrong. They are normalising it. It’s like they are warming up the mob.”

John Woodcock, the chair of Labour’s backbench foreign affairs committee, said Williamson’s comments appeared to be in direct contravention of Operation Constrain, the government policy dealing with returning jihadists by rehabilitating those for whom there is not enough evidence to prosecute.

“If he is not slapped down, any future enemy of Britain could say: ‘Why should we respect the Geneva conventions on captured British soldiers when the British don’t respect it for their own citizens?” he said.

Profile Who is Gavin Williamson? Show Before Westminster Born in Scarborough, North Yorkshire, he had a comprehensive education before going on to gain a degree in social science at the University of Bradford. Williamson then worked for a while in the pottery industry and for an architectural design firm before being elected MP for South Staffordshire in 2010 at the age of 33. A rapid rise Just a few years after his election, Williamson became David Cameron’s parliamentary aide, acting as his eyes and ears among MPs. But when Cameron stepped down, Williamson quickly threw his lot in with Theresa May as the most effective stop-Boris candidate and was adopted as her campaign manager. Having impressed with his organisational skills, he was elevated to chief whip, despite not having previously served as a minister. Appointed defence secretary After becoming pivotal in the deal with the Democratic Unionist party (DUP), Williamson earned May's respect for managing difficult parliamentary votes with the slimmest of DUP-backed majorities. His move into the cabinet after Sir Michael Fallon resigned over allegations of sexual harassment appeared to position him as a potential Conservative leader, but the backlash among MPs was significant. Spider man In Westminster he kept a tarantula called Cronus in a glass box on his desk, seemingly to intimidate MPs who had stepped out of line. The creature is named after the Greek god who came to power by castrating his own father before eating his own children to ensure they would not oust him. Gaffes in office Known for his colourful Instagram posts, Williamson was involved in a series of gaffes as defence secretary. As well as clashing with the prime minister over the publication of the government’s defence review, he angered the Chinese enough for them to cancel a trade trip by chancellor Philip Hammond, and was called 'the minister for war' by a Russian minister after his comments about the Skripal poisoning.



Good Morning Britain presenter Richard Madeley once cut off a live interview with him after he repeatedly refused to answer a question. It was all enough to earn him the nickname 'Private Pike' in Whitehall, in reference to the hapless youth in the sitcom Dad’s Army

Downfall Williamson was sacked as defence secretary by Theresa May after she "lost confidence in his ability to serve in the role of defence secretary and as a member of her cabinet". The move followed an investigation into who leaked sensitive National Security Council discussions about the Chinese company Huawei's involvement in the UK's 5G network infrastructure. Williamson has denied being the source of the leak, saying he was the victim of a 'kangaroo court'.

Paddy Ashdown, the former Liberal Democrat leader who served in the Royal Marines, said defence secretaries “should be measured, careful, judicious and thoughtful about what they say, not apprentice cadet versions of Donald Trump”.

The party’s defence spokesman and former leader, Menzies Campbell, said any member of the military who followed Williamson’s advice could be subject to court martial and prosecution.

Downing Street did not directly defend Williamson but said British jihadists should expect to be targeted.

“The government position on this has been made clear a number of times in recent months, which is that if you travel to Iraq and Syria, and if you’re fighting with our enemies there, then you make yourself a legitimate target,” said the prime minister’s spokesman.

“In instances where people do return to the UK, we’re clear that they should face the consequences of their actions and that would include investigation by the police and possible criminal prosecution.”

Max Hill, the independent reviewer of terrorism legislation, said recently that the UK could attempt to reintegrate young and naive jihadists who wanted to return to the UK.

More than 800 UK citizens are thought to have gone to fight for Isis in Iraq and Syria, including teenagers, women and young families. Hill said he believed there should be some space for rehabilitation of individuals such as the three teenage girls who travelled to Syria from east London.

“Even such teenagers would not escape prosecution if there is evidence that they have committed serious criminal offences, but if not, surely we should make an allowance for their return in circumstances where they were simply brainwashed, as immature and vulnerable teenagers,” he said.

On Thursday, Hill declined to comment directly on Williamson’s remarks, but said: “Criminal prosecution is inevitable in most cases where UK citizens return, and where [there is] evidence of committing serious criminal offences.”

Amnesty International UK’s director, Kate Allen, said: “In all circumstances, deliberately killing fighters who’ve surrendered or who’ve been captured or incapacitated is absolutely prohibited. It violates the laws of war as well as international human rights law, and is a war crime.”