At least 20 known jihadists are being tracked every day by police and MI5 in a bid to stop bloodshed on our streets.
It comes as the Tories pledged to end automatic early releases from jail of terrorists after Sudesh Amman’s knife attack in London.
A source said: “These are pretty intense situations.”
The speed with which Amman launched his ferocious terror attack on innocent victims shows just how tough the job of trailing dangerous jihadists is.
And the Mirror can reveal at least 20 Islamist suspects are under intense MI5 and police surveillance amid fears they could strike at any time.
Police stopped 20-year-old Amman causing any further bloodshed by shooting him dead after he stabbed two people during a rampage in Streatham, South London, on Sunday while wearing a fake suicide vest.
But there are fears things could be much worse if stretched officers cannot get to the jihadists quick enough.
A source said: “The number of potentially dangerous individuals being surveilled with the same intensity as Amman is in the early 20s.
“The worrying thing is that any of these targets could escalate suddenly and with no warning so these are pretty intense situations officers are putting themselves into.”
The Mirror can also reveal SAS soldiers were embedded in the counter-terror operation which ended in police shooting dead Amman.
Its military advisers helped police target the knifeman once it emerged he was bent on launching an attack.
Amman was freed from jail about a week ago after serving half of his sentence of three years, four months for distributing terrorist material.
The Government on Monday announced it would bring in emergency legislation to end automatic early release for 220 convicted terrorists still in prison.
The extraordinary step, which could happen as early as this week, means terrorist offenders will have to serve at least two thirds of a sentence before the parole board considers release.
There are more than 700 live probes into terror plots by MI5 and police and a further 23,000 individuals on file as being possible jihadists.
Amman’s early release from prison despite concerns he was still a danger sparked serious questions about the early release guidelines.
Justice Secretary Robert Buckland told MPs on Monday: “I have long been clear that automatic halfway release is simply not right in all cases. Yesterday’s appalling incident makes the case plainly for immediate action.
“We face a threat from an ideology that takes no heed for others and we must use every tool we can to make sure that threat is neutralised.” Boris Johnson said earlier that laws preventing automatic early release of convicted terrorists should apply to existing as well as future prisoners.
But the PM claimed rehabilitation rarely worked, amid criticism the Government was not doing enough to deradicalise prisoners. He added: “The instances of success are really very few and we need to be frank about that.
“I think the idea of automatic early release for people who obviously continue to pose a threat to the public has come to the end of its useful life.”
Ministers had set out tough new measures after the London Bridge attack last year, including longer sentences for serious terrorist offenders and using lie detector tests to assess risk as part of probation.
Ministers are braced for a legal challenge but are said to be determined to press ahead with the controversial move to retrospectively apply the new law. Clare Collier, of human rights campaign group Liberty, warned the Tory proposals on sentencing were “a cause of increasing concern for our civil liberties”.
She said: “From last month’s knee-jerk lie detector proposal, to today’s threat to break the law by changing people’s sentences retrospectively, continuing to introduce measures without review or evidence is dangerous and will create more problems than it solves.”
Shadow Policing Minister Louise Haigh said if Amman had served his whole term he’d probably be “even more dangerous” than when he went in to prison.
Shadow Justice Secretary Richard Burgon claimed Tory austerity was putting innocent lives at risk because of cuts to law enforcement.
He said: “Tragically, the cuts across our justice system to the police and to prisons, to probation and the CPS, have left communities less safe, which is why our justice system is in crisis.”
Amman, originally from Harrow, North West London, was staying in a bail hostel in Streatham when he launched his attack.
The site manager told how he last saw him on Friday. He said: “I set up his heating. He didn’t speak much.”
Scotland Yard said armed officers were following Amman on foot as part of a “proactive counter-terrorism surveillance operation”. They opened fire after he stole a 10inch knife from a shop and stabbed two passers-by.
The Met said: “Police officers responded, fatally shooting him within approximately 60 seconds of him beginning to attack people.”
But the force refused to reveal details of their surveillance operation as it could “undermine police tactics used to investigate terrorists”.
Amman’s victims were a 40-year-old man, who police said is no longer considered to be in a life-threatening condition and woman in her 50s, who had non-life threatening injuries and has been discharged from hospital.
A woman in her 20s was hurt by glass believed to have been broken by a police gun going off.
Daily Mirror online