AS MANY as 1,000 British jihadists who have been fighting in Syria and Iraq are feared to be back on the streets of the UK.
The chilling warning came as the hunt for the Briton who murdered US journalist James Foley was stepped up.
Ministers were last night urged to introduce tougher border checks to stop the Islamist fanatics getting back into the country.
MI5 has made tracking down the jihadists its No1 priority, fearing they could use their terrorist training to commit atrocities in the UK. Up to 2,000 Britons have travelled to Syria or Iraq to take part in the conflict there, according to Labour MP Khalid Mahmood.
He told the Daily Express yesterday that half that number could have already come back to the UK.
The Government estimates there are around 500 British fanatics among the Islamist fighters while a further 250 are thought to have returned to the UK.
But Mr Mahmood said inadequate border controls were hindering intelligence agency and police efforts to get to grips with the problem.
“There are no effective controls by the UK border forces on exit or return. No one knows what is going on,” he said.
“There is a real threat to the UK. I would say that up to 1,000 could have already come back here.
“Some are a threat on our streets now and some, who have been radicalised over there, might decide to reactivate themselves later on.”
It means there are now almost three times as many British Muslims fighting for the Islamic State militants as there are serving in our own Armed Forces.
Mr Mahmood, the MP for Birmingham Perry Barr, said people were using complex routes to get to Syria from the UK by flying to Turkey, Jordan, Egypt, Dubai or even south-east Asia.
He added: “But when they decide to come back, their passport is being given the green light.
“There needs to be more rigorous questioning. Where they have been? How long for? Why have they been there?”
Concerns over Britain’s porous borders were raised after the Government revealed it has seized only 23 passports this year to prevent fanatics travelling to the war zone.
Tory MP Mark Reckless, a member of the Home Affairs select committee, said: “Frankly I am sceptical that our border forces have anywhere near the capability to deal with this situation. It’s not just numbers but also a lack of intelligence.
“Intercepting these people is an enormous challenge and we must hope that our security services latch on to the most dangerous of these people before they become a threat.”
Ukip leader Nigel Farage has urged ministers to revoke the citizenship of Britons who become jihadists. Shadow Home Secretary Yvette Cooper accused ministers of failing to tackle the problem of young British Muslims being radicalised.
“The police and security agencies have warned for some time that hundreds of British citizens have been travelling to Syria to join Islamic State fighters,” she said.
“Much more needs to be done to prevent young British people getting drawn into this, identify those involved and prevent them posing a risk to the UK if they return.”
Ghaffar Hussain, of the counterextremism think tank Quilliam, said work by the police and MI5 to prevent violent attacks had so far been effective.
But he warned: “It’s not just people who are going to fight that we should be concerned about.
“There are also disturbing numbers of people in this country who are sympathetic to the militants.
“We need a wave of civil society activism that takes on extremist narratives.”
They range from a star medical student to a petty criminal.
Whether sons, fathers, daughters or sisters, they gave up their lives in the West to join Islamic State fighters.
Abu Abdullah Brittani is one of 10 British jihadists from Portsmouth, Hants, to join the IS in Syria. The 32-year-old has popped up on internet chatrooms – telling one person on the Ask.Fm site: “After training you get an AK47, a vest pack and a grenade.”
Twins Salma and Zahra Halane, 16, from Chorlton, Manchester, have 28 GCSEs between them and were hoping to study medicine. They ran away and travelled to marry jihadi warlords in IS-held Raqqa.
Amer Deghayes is one of three brothers from Brighton who travelled out separately. His brother, university student Abdullah, 18, was killed in a firefight in Latakia. Amer, 20, said: “His death was a sign of martyrdom. As he fell back he laughed and smiled.”
Nasser Muthana, 20, from Cardiff was a would-be medic who had been offered places at four separate universities but rejected them all and fled east. Aine Davis, 30, has convictions for possessing a firearm and cannabis. He left London’s squalid gang culture to join the Al Qaeda offshoot.
Father-of-three Abdul Waheed Majeed, 41, from Crawley, West Sussex, became the first British suicide bomber in Syria. He died when he drove a vehicle packed with explosives into Aleppo in a bid to free hundreds of jihadists.