More than 3,000 jihadis are in the UK – stretching the country’s security services to breaking point.

Spies and counter-terror police are struggling to monitor a flood of suspects, mainly radicalised men and women in their teens and early 20s.

About 850 Britons are thought to have gone abroad to fight with so-called Islamic State as they took control of large swathes of territory in Syria and Iraq.

Armed police on patrol in central Manchester, Britain the day after the Ariana Grande terror attack

Concert-goers scramble over chairs after hearing the bomb outside

But with the terror group being pushed out, extremists with British passports are fleeing back to the UK where authorities fear they may unleash a new wave of attacks.

Although more than 100 have been killed, around half have returned home with battle experience and training in the use of explosives and firearms.

WHY THE UK GAVE SANCTUARY TO EXTREMIST ENEMIES OF COLONEL GADDAFI Britain gave sanctuary to enemies of Libyan leader Colonel Gaddafi – even though some had links to Muslim extremists. Hundreds of political opponents of the tyrant were given asylum during the 1980s and 1990s. Some of them belonged to the hardline Libyan Islamist Fighting Group. At least one Libyan was based in Manchester, and frequented Didsbury mosque, one of the main centres of anti-Gaddafi activity in Britain. But the men were betrayed as Britain sought Libyan help with extremists in the wake of the 9/11 attacks. Advertisement

The security services have also foiled at least 13 planned attacks in the past four years, Britain’s most senior counter-terrorism officer, Acting Deputy Met Commissioner Mark Rowley, has revealed.

The figures lay bare the scale of the terror threat facing the country from extremists.

The flood of new jihadists is stretching the UK’s security services to breaking point, with up to 30 officers required to provide 24-hour monitoring of just one suspect. Restricted resources mean MI5 can watch around 50 terror suspects around the clock.

As well as sophisticated plots to bomb transport hubs and shopping centres, jihadists in the UK are being groomed – often online – to carry out ‘lone wolf’ attacks using knives and vehicles.

A chilling report also revealed that the wives and children of Islamic State fighters in Syria could be brainwashed into carrying out attacks after returning to Britain. Europol, the EU’s police intelligence agency, said many posed a grave danger because they had been radicalised and desensitised to extreme violence.

In 2016-17, there were 380 terrorism-related arrests in the UK, compared to 307 in the previous 12 months – a rise of nearly 25 per cent. Anti-terror police stepped up arrests after Muslim convert Khalid Masood killed four pedestrians on Westminster Bridge in March before stabbing a police officer to death. Meanwhile, in the past three years there were 386 terror-related convictions, according to figures from Scotland Yard.

THEY’RE JUST ‘EVIL LOSERS’... TRUMP LEADS CONDEMNATION Donald Trump led international condemnation of the Manchester atrocity by branding bomber Salman Abedi an ‘evil loser’. President Trump told Theresa May in a phone call that the US stood in solidarity with Britain following the massacre which killed at least 22 people. He offered Mrs May assistance in the investigation and they agreed the targeting of children at a concert was ‘particularly wanton and depraved’, the White House said. Donald Trump (pictured in Bethlehem yesterday) led international condemnation of the Manchester atrocity The call came shortly after Mr Trump denounced those responsible for the atrocity as ‘evil losers’ and said the ‘wicked ideology’ should be ‘completely obliterated’. Newly elected French president Emmanuel Macron called Mrs May to offer his condolences and expressed his ‘horror and shock’ at the attack. German Chancellor Angela Merkel assured Britain that ‘Germany stands at your side’. Vladimir Putin also offered to boost anti-terror co-operation with the UK after the ‘inhuman’ attack at the concert. Former US president Barack Obama said: ‘Our hearts go out to those killed and wounded in Manchester. Americans will always stand shoulder to shoulder with the people of the UK.’ Advertisement

Only seven extremists in Britain are under anti-terror orders watered down thanks to the Lib Dems

Only seven extremists have been placed under anti-terror orders watered down at the behest of the LibDems despite there being at least 3,000 fanatics at large in Britain.

The so-called T-Pims - Terrorism Prevention and Investigation Measures - are the toughest tool the security services have to restrict the activities of terror plotters and sympathisers.

They replaced the more restrictive Control Orders which were axed in 2011 at the bidding of then Liberal Democrat leader Nick Clegg following a row over human rights.

Armed police on patrol in Manchester the day after the concert attack

T-Pims are supposed to ensure that the police and MI5 can protect the public from UK-based fanatics who cannot yet be prosecuted or deported by placing curbs on their movements and activities.

Restrictions can relate to overseas travel and place of residence, and limits can be imposed on the possession and use of electronic communication devices.

Suspects can also be required to live in a property up to 200 miles away from their home.

But a statement slipped out to Parliament in December revealed that, as of the end of November, only seven T-Pims were in force.

By contrast, in the months after the Paris attacks in 2015, almost 400 people were placed under house arrest in France by the authorities there.

British courts have been accused of weakening T-Pims by chiselling away their conditions and making it very difficult for the security services to secure them.

This has meant that they have become reluctant to seek them, fearing that they would be squandering thousands of pounds of taxpayers’ money on legal fees for little gain.

Chris Phillips, the ex-head of the national counter terrorism and security office, said he did not believe the current regime of T-Pims was working.

He said: ‘The number of people subjected to T-Pims is far too low given the number of extremists concerned.

Police and other emergency services are seen near the Manchester Arena

‘It really should be in the hundreds. If it is worthwhile monitoring theses fanatics, then ministers should not shy away from it.

‘The last Government watered the sanctions down but they may need to look at beefing them up again. They cannot brush this issue under the carpet any longer.’

Last year Keith Vaz, then Labour chairman of the Commons’ Home Affairs Select Committee, suggested Prime Minister Theresa May looked at bolstering the T-Pims ‘given that she had been under pressure from her Liberal Democrat colleagues in the Coalition government to abandon control orders.’

And in 2014, Lord Carlile, a LibDem peer who was the independent reviewer of terror legislation for 10 years, said control orders had been abandoned for ‘political reasons’. He added: ‘The evidence is clear that the absence of anything like control orders… is harming the ability of the authorities to restrict the activities of people that they identify as threats.’

Britain is currently facing a heightened terror threat.

In March, IS sympathiser Khalid Masood, 52, murdered five and injured more than 50 in a vehicle-and-knife rampage outside Parliament. The fanatic was shot dead during the attack.

The UK’s terror threat level is currently ‘severe’ - the second highest level - amid warnings that a jihadist atrocity is ‘highly likely’.

Concert goers wait to be picked up at the scene of Monday night's terror blast

Security chiefs have warned that hundreds of young Britons who joined Islamic State jihadists in Iraq and Syria have returned home, while others have brainwashed ‘lone wolf’ Muslims to carry out attacks.

Control orders were introduced by Labour to deal with dangerous extremists who not be hauled before the courts but after 2010 they came under fire from the Lib Dems who said they were unfair because the suspects had not been found guilty of a crime.

Under these suspects faced 16-hour curfews, an electronic tags, bans from meeting named individuals and using mobile phones and the internet, and could be forced to relocate to other parts of the country - ensuring they were not in touch with any jihadist allies.

They were replaced by T-Pims with a reduced curfew requirement of ten hours and suspects were no longer restricted on where they could live.

Terror suspects placed on control orders and T-Pims could also be required to surrender their passports so they could not travel outside Britain

In an extraordinary security fiasco in February 2014, controls on seven of the most dangerous terror suspects in Britain – including two fanatics linked to the liquid bomb airline plot – were lifted and never renewed.

It meant they were free to walk the UK’s streets under a cloak of state-sanctioned anonymity.

Control orders were themselves a replacement for measures introduced in the wake of the September 11 attacks which allowed foreign national terror suspects to be detained indefinitely without trial. The measures were declared incompatible with human rights by Law Lords in 2004.

No histrionics from Theresa - just controlled, civilised outrage: QUENTIN LETTS on the PM’s most powerful Downing Street statement

Prime Minister Theresa May walks to deliver a statement on the Manchester Arena terror attacks outside 10 Downing Street

A nearby clock tower had just tolled 11am when a plainly affected Theresa May stepped out of No 10 to make a statement about the killings. Normally the mood in Downing Street before a Prime Ministerial appearance crackles with chatter. Yesterday the mood of the Press corps was subdued.

The shiny black door swung open and photographers’ shutters click-click-clicked. There was no other sound. No helicopter droned overhead, as sometimes happens.

No crowd of protesters jeered slogans at the distant gates. And there were no lensmen’s exhortations of ‘over here, Theresa’, when they try to get her to look their way. Not yesterday. Just silence.

She was in black trouser suit, black, flat shoes, respectful jewellery, tidy hair. The narrow legs of that trouser suit accentuated her slim-shouldered frame, more vulnerable than you might expect. As she came out of the doorway I was struck by how fragile and lonely she looked.

Although on show, she retained a contemplative, sombre air. In some ways it was the expression of a churchgoer returning to her place after communion.

Of course, she is the least lonely person in the country, constantly surrounded by aides and bodyguards and general to-do. Yet terrorism makes an island of the person at the top. She was the one who had to make the decisions and find words to reassure the nation. How to describe the indescribable? There was a pause as she braced herself for the off. Then: ‘I have just chaired a meeting of the Government’s emergency committee where we discussed the details of and the response to the appalling events in Manchester last night.’

And she was launched on a long, powerful statement in which she averred that ‘the spirit of Manchester and the spirit of Britain’ would prevail. It was a spirit that ‘through years of conflict and terrorism has never been broken’ and never would be, she said. Her cadence turning Churchillian, she conceded ‘there will be difficult days ahead’ but the terrorists would not win.

Mancunian and British solidarity would prove insuperable. The one chink in its armour, perhaps, came when she mentioned the children who had died, and the voice momentarily wobbled.

May speeches are not always memorable. She can sometimes sound prosaic, the larynx doing that warbly, headmistressy thing. Not yesterday. She had not had any sleep and her timbre had sunk a note or two. Her weariness, stark lipstick contrasting with her pale skin, lent her grit. Though physically weary, she was tough inside.

People lay tributes at a vigil for the people who lost their lives during the terror attack in central Manchester

Downing Street makes a theatrical setting. The building’s facade is as flat as any stage back-wall and the bluey greyness of the old brickwork was lifted by sunshine.

Two fine British bobbies stood on duty, out of TV shot but either side of No 10. Suited detectives guarded the Jaguar waiting to whisk her north. A few Foreign Office staff stood behind a large, wrought-iron gate directly opposite Mrs May, watching her, rapt.

One of them was a woman in Muslim head-dress. Attempts to divide our society would not succeed, said Mrs May.

She cited the ‘countless acts of kindness’ that had been seen in Manchester after the attack. The images we hold in our minds should not be those of the senseless slaughter but of the ordinary men and woman who put concerns about their own safety to one side and rushed to help.’

Donald Trump, in his own, direct and welcome way, may have mocked the terrorists as ‘losers’ but vicar’s daughter Mrs May was finding her own way of asserting our values. There was nothing boastful or histrionic in her remarks. She voiced a controlled, civilised outrage at this assault on Manchester’s defenceless children and their families.

Our Prime Minister – and yes, that is very much what she sounded yesterday – is not a woman given easily to emotion. In the past some have accused her of being robotic. Not yesterday, they wouldn’t have done.

Not yesterday. She was poised, sympathetic, sturdy. She spoke her piece well.

Singer Ariana Grande performs onstage in a reveal outfit

JAMES HARKIN: How Ariana Grande and her revealing stage outfits are a symbol of everything Islamists hate

Now that it seems likely the atrocity in Manchester was carried out by a freelance 'soldier' allied to Islamic State, there's good reason to think neither the venue nor the performer were chosen at random.

Why would anyone target a concert by the American singer Ariana Grande? The grim answer may lie in the fact that with her revealing stage outfits, her stockings, pink bunny ears and unabashed sexual confidence, 23-year-old Miss Grande is a symbol of everything Islamists hate.

According to the purist, medieval interpretation of the Koran favoured by Islamic State, almost everything about Western music, and the Western lifestyle that goes with it, is haram, or forbidden — and so merits a death sentence.

Indeed, one claim of responsibility for Monday's attack stated: 'The explosive devices were detonated in the shameless concert arena.'

Those unfortunate enough to live in Islamic State's caliphate have experience of this doctrine.

Three years ago, the then fledgling Islamic State issued a statement that read: 'Songs and music are forbidden in Islam, as they prevent one from the remembrance of God and the Koran, and are a temptation and corruption of the heart.' The directive went on to cite Koranic verses and Islamic teaching.

One young Syrian I met when I was reporting in the region, who lived in the group's de facto capital of Raqqa, told me dolefully his best friend was thrown in jail for wearing a Metallica T-shirt celebrating the U.S. rock band.

At the many checkpoints through which Syrians had to pass on their way out of Islamic State territory (back when they were allowed to leave), the militants paid as much attention to the length of men's beards and contents of their mobile phones as to their politics.

Guards, many of them no more than boys, diligently searched mobile phones for any minor infractions of their religious laws: and that included music that 'insulted' Allah.

In their sliding scale of punishments, I was told, a single pop song was rewarded by between 30 and 40 lashes with a whip or stick. In another incident in 2015, a group of musicians was reportedly sentenced to 90 lashes each for the 'crime' of playing an electronic keyboard.

Concert-goes scramble to the exit after the bomb blast

Like medieval inquisitors, converts to the Islamic State see Satan (shaytan) and supernatural beings (jinns) everywhere and in anything.

In Syria and Iraq, their feared religious police (the hisbah) pay particular attention to teenage heavy metal music fans, which they consider the devil's work.

Women are treated as inherently suspicious, and are forced to cover up and wear the face veil when outside and never to leave home without a chaperone.

Thus the sight of Ariana Grande and her risque stage outfits would be anathema to the fanatics.

In territory controlled by Islamic State, everything from pop music to musical instruments are banned as totems of godless Western decadence.

That's why a group of masked Isis fighters were photographed two years ago in Libya — the country from which the Manchester suspect's family hail — burning a saxophone and drums.

Even before Islamic State moved to create its state in the ruins of Syria and Iraq, there were signs this extremist sensibility was taking root among disgruntled young Muslims in our inner cities.

In 2004, British police secretly recorded a cell of young Islamists discussing a possible attack on a London nightclub, on the basis that no one could 'turn round and say 'Oh, they were innocent', those slags dancing around'.

Likewise, a car bomb parked outside Tiger Tiger nightclub in London's Piccadilly in 2007 seems to have been designed to coincide with a 'ladies' night' at the venue, in which the perpetrators might have hoped to kill and maim scantily clad young women drinking alcohol.

The vehicle was packed with 60 litres of petrol, gas cylinders and nails, and would have caused 'carnage', police said, if the bomb had not failed to detonate.

(One great irony is that many of these young Islamists have a past of drug-dealing, debauchery and petty crime. Indeed, given all their injunctions against Western music, it's striking how many of those who travelled to the Islamic State from Britain — such as Londoner Abdel-Majed Abdel Bary, once photographed in Syria holding a severed head — were failed rap musicians.)

Harkin writes: 'Miss Grande (pictured at the 42nd annual American Music Awards) is symbol of everything Islamists hate'

Now, as Islamic State territory in the Middle East is whittled away, its propaganda is urging supporters to strike back against 'disbelievers' by seeking out more music venues and nightclubs.

So it was that an Islamic State gunman attacked a nightclub in Istanbul in the early hours of New Year's Day this year, killing 39 of that city's wealthy young set.

Islamic State also directed the appalling massacre of 89 people at the Bataclan concert hall in Paris in November 2015.

On that night, a gig by the U.S. rock band Eagles of Death Metal was targeted with automatic rifles, grenades and suicide bombs as the jihadis made a blood-soaked statement against Western music and the lifestyle that goes with it.

These Islamist puritans believe our Western way of life is on the verge of collapse and see their job as sending it to hell as quickly as possible.

Their war is not so much with our governments as with the values we all live by, which is why they are prepared to slaughter innocent little girls clutching pink balloons on a night out with their mothers at a pop concert.

James Harkin is director of the Centre for Investigative Journalism and a reporter on Syria and the rise of Islamic State.