Only 40 of the 400 British jihadis who fought in Syria and Iraq have been prosecuted on their return home.

At least 360 battle-hardened fanatics are being allowed to go free because there is too little evidence to convict them.

The figures, disclosed by security minister Ben Wallace, will raise concerns over whether the authorities can keep track of all the dangerous extremists on our streets.

Police chiefs have repeatedly warned of the severity of the terror threat facing Britain – particularly from those who have been radicalised by fighting abroad.

John Woodcock, the Labour MP who had pressed for the release of the figures, said: ‘It’s no wonder the Government tried to keep secret that it has only managed to prosecute one in ten of the British jihadis returning from Syria.

A masked, black-clad militant, who has been identified by the Washington Post newspaper as a Briton named Mohammed Emwazi, in a still image from 2014

Anjem Choudary arriving for a court hearing at the Old Bailey in March 2016

‘It is an affront to our country that the difficulty of amassing admissible evidence means there is no comeuppance for people who went to aid an evil regime that wanted to slaughter British civilians.’

He said it should be made illegal to travel to terror hotspots without good excuse. This would mean evidence would not have to be produced to prosecute suspected fanatics.

Ex-jihadi gets handed job and a flat A jihadi returned from fighting on the frontline in Syria to take up a job as a food delivery driver in London. The only sanction the 34-year-old faced was the cancellation of his British passport, ensuring he can now never leave. Despite once being a right-hand man of hate preacher Anjem Choudary he was not put on trial Despite once being a right-hand man of hate preacher Anjem Choudary he was not put on trial. Instead the man, who can be identified only by his pseudonym Abu Rayah, was given a council flat in east London. He took up a job working as a driver for a restaurant, delivering takeaways to the homes of customers via food app Just Eat. Rayah, who once worked for the NHS, travelled to Turkey in February 2014 under the guise of a two-week family holiday. From there, he entered Syria for up to four months to engage in terrorism-related activity, probably including warfare. Advertisement

The last time the Home Office revealed the number of returning foreign fighters taken to court was in 2016. Then it stood at 14. Speaking in a Commons debate on Monday, Mr Wallace said: ‘Approximately 40 have been prosecuted so far – either because of direct action they have carried out in Syria or, subsequent to coming back, linked to that foreign fighting.’

The 40 figure refers to successful prosecutions. More will have faced charges that did not stick.

Mr Woodcock, a member of the Home Affairs select committee, said the low prosecution rate showed ‘how urgently we need to toughen our terror laws’.

He cited Australia’s declared areas offence, under which its citizens risk ten years in jail for travelling to Iraq or Syria.

Home Secretary Sajid Javid said he would be ‘looking at just that’, adding: ‘There’s a bit more work to do on it, it’s not as straightforward as it might sound.’

‘The honourable gentleman mentions the Australian extraterritorial offence that has been created, and I am looking at just that. If it is to become a legislative proposal, I obviously want to make sure that we have considered it properly.’

Around 850 Britons are believed to have travelled to Syria or Iraq and at least 15 per cent of them are thought to be dead.

Security service chiefs and counter-terrorism officers fear those still there might try to return to the UK as the so-called caliphate is wiped out.

Several have also been detained in the region and their fate remains uncertain. They include Alexanda Kotey and El Shafee Elsheikh, suspected members of the group nicknamed ‘The Beatles’, which murdered British and American hostages as well as Syrian soldiers.

Ministers are yet to agree on what to do with captured foreign fighters. If they are brought back to face trial there is a risk that there will not be enough evidence to convict them.

The low figure of those prosecuted when they return demonstrates the scale of the challenge facing the Government.

Police officers have been preparing for battle-hardened foreign fighters to return to the streets of Britain by carrying out mock exercises with soldiers.

British troops armed with AK-47s, knives and fake bombs posed as extremists carrying out a mass casualty attack during a pretend play at a theatre near Bishop Auckland in County Durham.

300 members of Durham and Cleveland police, the fire brigade and ambulance service, as well as 120 volunteers, took part in Exercise Root last September.

The eight soldiers from 1st Infantry Training Battalion, based at Catterick, North Yorkshire, were mainly Iraq and Afghanistan veterans took on the role of a ‘military-trained enemy’.

They were drafted in to take part in the exercise because they had experienced combat and could pretend to be returnees who have been to terror training camps in the Middle East and Africa or fought on the frontline with Islamic State.

They were drafted in to take part in the exercise because they had experienced combat and could pretend to be returnees who have been to terror training camps in the Middle East and Africa or fought on the frontline with Islamic State

Major Andy Witherell, the battalion’s second in command, told the Mail earlier this year: ‘Our partners in Northumbria were planning a counter terrorist exercise.

‘Normally they use their own people as a terrorist enemy force.’

But he said they ‘wanted a demanding enemy, not just someone who would roll over and die’.

Major Witherell said: ‘One of the concerns police and security services seem to have is people who have combat experience in Iraq and Syria returning to the UK.

‘They therefore pose a more complex threat to the security services and the police.

‘It was suggested who better to play that role than soldiers with combat experience.

‘Police want to test their teams to train against the threat.’

He went on: ‘We have soldiers who can replicate those returning fighters but also those who can replicate attacks we have seen in the UK.’

Ben Wallace told the Mail last night: 'This new Counter Terrorism legislation is vital for us to be able to deal with foreign fighters.

‘We are determined to deal with the threat.'