fighting for ISIS than serving in the British Army

The British Black Beatle who murdered journalist James Foley is one of at least 500 Britons fighting for ISIS - and 250 of them are believed to back already

At least one in four of the estimated 2,000 foreigners fighting for ISIS in Syria and Iraq is British - and half of those are already back in the UK, it has emerged today.

Serious questions have been raised as to whether enough is being done to stem the flow of fighters after the Government revealed it has only seized 23 passports this year to prevent them travelling to the war zone.

The Government says there are around 500 British among the fighters while a further 250 are thought to have already returned to the UK where the police and security services are attempting to watch them.

That means there are now almost three times as many British Muslims fighting for Islamic State than there are serving in the UK military, an MP has claimed.

But Khalid Mahmood, Labour MP for Birmingham Perry Barr, told Channel 4 News the lack of border controls meant the Government’s estimates of jihadi numbers were too low. ‘I think it’s about 2,000 people,’ he added.

According to the Ministry of Defence, there are around 600 British Muslims currently serving in the Armed Forces - just 0.4 per cent of total personnel. This is far below the 4.3 per cent of the British population as a whole who are Muslim.

Irish police also believe that 30 jihadists are using the country as a base while travelling to and from Syria and Iraq.

The murder of James Foley apparently by 'John' - one of a gang of British jihadis known as 'The Beatles' - has raised fears the killing fields of Syria and Iraq are dominated by extremist Britons.

The security services are using advanced voice recognition techniques to try to identify the murderer seen in the five-minute IS video, which has been viewed by thousands of people online.

The Briton, who uses his left hand and wears Timberland boots, speaks with what appears to be an East London accent.

Obscene: The video uploaded on Tuesday showed the British IS fighter - called 'John' - murdering Mr Foley with a knife

In the video, the masked killer gives a statement directly to the camera blaming President Barack Obama for the death of the American, who is seen dressed in a Guantanamo-style orange jumpsuit as he kneels in the sand. The man then carries out the beheading, before warning that another American hostage could be next.

Experts also say they are also the most 'arrogant, vicious and vociferous' jihadists - and have been able to fly with ease fly to Istanbul in Turkey and jump on a bus to get into neighbouring Syria.

Here are some of the most notorious Britons fighting for ISIS:

Abu Abdullah Al Brittani

Abu Abdullah Al Brittani, 32, who used a social network to produce a travel guide for would-be jihadists

The 32-year-old is one of ten Britons from Portsmouth to travel Syria to fight for ISIS.

A British jihadist who says he is fighting for ISIS has attempted to lure a child away from his parents with chilling online travel advice on how to reach the Middle East.

A man calling himself Abu Abdullah Al Brittani gave detailed information on how Iraq-bound Westerners can exchange currencies to an Ask.Fm user who described himself as 'underage', said he had never travelled alone before, and expressed concern about his mother and father finding out.

The post outlines ISIS' openness to luring Western fighters of all ages to their cause - including an estimated 500 Britons, many of whom end being used as little more than 'cannon fodder' to protect better trained local jihadists.

Abu Abdullah was behind an Ask.Fm travel guide for would-be jihadists that formed part of an attempt to recruit young Britons to Iraq and Syria.

One user asks him: 'I havent any traveling and i'm underage but what do you mean with no worries about money. honestly I don't know how to change money into tukish or syrian money. How does it work? I can't ask my parents or they will now [sic]'.

Despite the poster admitting he is a child and exhibiting clear naivety, Abu Abdullah responds: 'If u have $ or £ then u fine, any other currency exchange it to $ or £ before u get here and [God willing] u will be fine [sic].'

Another message describes the 'welcome pack' new ISIS recruits receive when they complete theIr induction process.

'After training u get a ak47 and magazines (4) a vest pack, grenade [sic]' he posted on Ask.Fm.

Another message contains detailed marriage advice for potential recruits.

Muhammad Hamidur Rahman

Primark supervisor Muhammad Rahman left his high street job for Syria, but died in a gunfight

A former supervisor at Primark who wanted to join the world’s most feared terrorist group, only to be killed in Syria.

Muhammad Hamidur Rahman, 25, from Portsmouth, was shot dead in a gun fight in July, a day before the Muslim festival if Eid, said his family.

His father, Abdul Hannan, 52, an Indian restaurant worker, said the family received a text message from a friend of Rahman in Syria who informed them that their son was dead.

Rahman is the second British jihadist from Portsmouth to die in Syria. The first was his friend Iftekhar Jaman, 23, who died in December.

Rahman’s father, Mr Hannan, said that Jaman went to Syria first at the beginning of last year, and then took his son there by contacting him through social media.

He said that Rahman did not tell any member of his family that he was going to Syria, but suddenly disappeared from Portsmouth. Days later, they received a call from him saying he was in Syria.

Mr Hannan said: ‘He asked us to pray for him, and said he wanted to become a shaheed (martyr) for the sake of Allah.’

Mashudur Choudhury

Mashudur Choudhury, 31, became the first Briton to be found guilty of travelling to Syria to fight in the civil war. He failed the selection process to join extremisrs and blew cash borrowed from his family to get there on foreign holidays, a luxury car and prostitutes

He became the first Briton to be found guilty of travelling to Syria to fight in the civil war.

Police said the conviction of Mashudur Choudhury, 31, was likely to pave the way for others returning from the fighting to be prosecuted.

The father of two went to fight with Al Qaeda to escape the shame of lying to his family about suffering from cancer.

Choudhury, from Portsmouth, borrowed £35,000 from his family, claiming it was for medical treatment.

But he blew it on foreign holidays, a luxury car and prostitutes.

Desperate to atone for his actions and ‘make something of himself’ he resolved to become a martyr fighting the brutal regime of Bashar Assad.

But he is believed to have failed the selection process to join a hardline group of Syrian rebels and was thrown out of their training camp in disgrace.

He was arrested by British anti-terror police on his return to Gatwick in October last year.

After a 12-day trial at Kingston Crown Court, West London, Choudhury was found guilty of engaging in conduct in preparation for terrorist acts.

Ifthekar Jaman

Ifthekar Jaman, 23, died last year in a battlefield clash 2,000 miles from his Hampshire home last December after bragging how life in Syria was '5-star' jihad

The young Briton boasted of fighting ‘5-star jihad’ in Syria but was killed.

Ifthekar Jaman, 23, died in 2013 in a battlefield clash 2,000 miles from his Hampshire home last December.

He was one of an estimated 350 British men to have taken up arms with Al Qaeda-linked groups in Syria – where they are known as British Kataa’ib, meaning British Brigade.

Jaman declared he was ready to die as a martyr, vowing: ‘I don’t plan to come back. Life is for the hereafter... it’s an eternal paradise so the sacrifice is small.’

He also urged fellow Britons to join him, using his Twitter account to glory in his hate-filled missions.

He described fighting in Syria as ‘5-star jihad’ because of its ‘relaxing’ nature.

Photographs showed Jaman – a supporter of fanatical British cleric Anjem Choudary – apparently manning armed checkpoints in the Middle Eastern war zone just before his death.

Salma and Zahra Halane

'Terror Twins' Salma and Zahra Halane, both 16, who have 28 GCSEs between them, fled Manchester for Syria, have married warlords and hope to train as doctors to treat ISIS fighters

Schoolgirl sisters fled Britain to join ISIS and marry warlords and admitted their pride at being known as 'Terror Twins' and 'loves' living in Syria.

Salma and Zahra Halane, both16, who have 28 GCSEs between them, ran away from their family in Chorlton, Greater Manchester, a month ago for 'paradise' in the war torn Middle East.

They have vowed never to return home after following their brother to Syria and social media updates suggest the pair are training to use grenades and Kalashnikov rifles.

The twins are now believed to be based in Raqqa, Syria - an Isis stronghold - where they are said to have already married fighters.

The sisters were hard-working students who hoped to train as doctors.

One recent tweet from their account said: 'Training to be doctors to Training to be killers... I will become a doctor for Isis not for these pagans'.

The pair left Manchester after sneaking from their bedrooms in the middle of the night and caught a flight to Turkey, before crossing the border into Syria.

Police said the pair are thought to have followed their elder brother, who also ditched his own ‘excellent’ academic career to join the ISIS terror group around a year ago.

Jaffah, Amer and Abdullah Deghayes

Brothers Abdullah 18, Jaffar, 16, and Amer Deghayes, 20, pictured, are fighting in Syria. Amer described how his brother died with a 'laugh and a smile' because he believes he became a martyr

Brighton University student Abdullah Deghayes, 18, was killed in a gunfight in Kassab in Latakia. His two brothers, Jaffar, 16, and Amer, 20, remain in Syria.

Jaffar is considered the youngest Briton to have gone to fight for ISIS.

In June Amer described his brother's death and said: 'My brother was killed on the frontline, when he was the furthest person in the front.

'When he ran in, the army actually ran away and retreated, so he was killed for a really good cause, and his death was a sign of martyrdom. As he fell back, he laughed and smiled.

'I have a really strong feeling that he is alive. I do strongly believe that he is alive and we believe martyrs are not dead, they are still alive and enjoying themselves.'

Nasser and Aseel Muthana

Aseel Muthana, 17, left, followed his older sibling Nasser, 20, right, from Cardiff to join Isis in Syria, who became a poster boy for ISIS as they attempt to recruit more Britons

Aseel Muthana, 17, followed his older sibling Nasser, 20, from Cardiff to join Isis in Syria.

In February Aseel fled Britain to fight in Syria after telling his parents he was staying at his friend's house ahead of a maths exam at his school.

But police then arrived at his home the following night after it emerged he had gained a second passport by lying about his age and was in Cyprus and about to sail to Syria.

His brother Nasser was a star medical student who secretly travelled to Syria from his family home in Cardiff despite being offered the opportunity to study medicine by four universities.

His family have not seen him since November 2013 and he reappeared as an ISIS poster boy on one of their propaganda films.

Furious father Ahmed Muthana, 57, said if his sons ever return to the UK, he would like to see them jailed.

He says the Welsh capital is facing a crisis with extremists leafleting communities and holding 'pop-up' events to groom young men.

Reyaad Khan

Reyaad Khan, also from Cardiff, appeared in a shocking recruitment video aimed at luring jihadists to Syria and could face a war crimes trial as he repeatedly uploaded bloodthirsty posts and pictures on social media

Reyaad Khan, also from Cardiff, appeared in a shocking recruitment video aimed at luring jihadists to Syria and Iraq.

He could face a war crimes trial as he repeatedly uploaded bloodthirsty posts and pictures on social media bragging about the inhumane killings.

In one he posted graphic photographs of the distorted corpses of alleged victims, tweeting: ‘Guys we caught & executed. This is how they looked less than an hr l8er’.

The former college student from Cardiff also laughed about witnessing the ‘longest decapitation ever’ and boasted in another: ‘Executed many prisoners yesterday.’

His claims about his involvement in the crimes carried out by a unit of ISIS are now being investigated by the United Nations.

Khan, who once dreamt of becoming Britain’s first Asian prime minister, could see his name added to the investigators’ list of suspected war criminals in Syria for future prosecution.

Aine Davis

Former drug dealer Aine Davis left his wife for Syria. She was found guilty of trying to send cash to him. The gangmember also asked her if he could take more wives

Career criminal Aine Davis grew up in a leafy London suburb, born to a mother who now works as a dinner lady and a father who sold clothes at John Lewis.

He is fighting with ISIS in Syria, and has swapped family portraits for poses in combat fatigues, surrounded by rebel soldiers holding AK47s.

The 30-year-old was at the centre of an Old Bailey trial last week that saw his wife, Amal El-Wahabi, jailed for funding terrorism while university student Nawal Msaad, 27, was sensationally cleared of trying to smuggle £16,000 in her underwear to Syria.

Throughout the trial, the jury heard that El-Wahabi, the mother of Davis's two children, was sending him money in the Middle East.

The pair would keep in contact via WhatsApp, with Davis sending her photos of him as a jihadi soldier alongside messages urging her to join him. He also asked if it was okay to have more wives.

A petty criminal and drug dealer adopting the nickname 'Biggz' while part of a London gang.

When he was just four-years-old, he was sent to Gambia to live with his grandmother, because he drove his mother 'crazy'.

Abdul Waheed Majeed

Abdul Waheed Majeed was a father-of-three from Sussex who became the first Briton to blow himself up

The father-of-three was the first Briton to blow himself up.

Laden with home-made plates of armour akin to the film Mad Max, he drove at high speed towards a jail in Aleppo, Syria, before detonating in a huge explosion which killed Majeed and dozens of Syrians.

Rebels initially claimed up to 300 inmates were able to escape.

The video was reportedly shot by fighters with the al-Qaida-linked Jabhat al-Nusra rebel group and begins with footage of the truck, followed by shots of fighters exchanging heavy fire.

The rebel group said the suicide bomber was called Abu Suleiman al-Britani, a pseudonym indicating his British origins.