There has been a purge of extremists and potential terrorists working on London’s transport network to guard against another Islamic State attack, the Government’s security minister has revealed.

Ben Wallace said Britain faces an “acute” terror threat, and the move would help police and emergency services in their fight to keep Londoners safe, following four successful attacks by radical Muslims in the capital last year.

He told the Evening Standard there had been an intensive effort to identify potential attackers and those who “would pose a risk to London and its transport network” had already been removed from their jobs on the network.

London Bridge terrorist Khuram Butt had a customer safety job on the London Underground network before becoming an Islamic State killer, which he could have used to strike trains. The 2005 7/7 bombers also famously attacked the Tube and a London bus (pictured).

UKIP spokesman and Lonon Assembly member Peter Whittle commented: “This is truly alarming. But anybody bringing this up before would have been called alarmist and scaremongering.”

Media source: police have identified a suspect from CCTV footage. https://t.co/TopY1Fcdfk — Breitbart London (@BreitbartLondon) September 15, 2017

Last year, it was revealed that there are at least 23,000 extremists and jihadists in Britain that the police have previously investigated or monitored, with around 3,000 under active scrutiny.

“We’ve done a lot of work over the last year about people working in sensitive areas who shouldn’t be, and removing their ability to do so,” Mr Wallace said.

“It’s reducing the insider threat. There are definitely people who have worked in sensitive areas that we have now removed who would pose a risk to London and its networks of transport.

“We’ve got to protect as well as pursue. There are more things we can do around where these people work.”

He added: “We have an acute number of people in this country who are attracted to extremism or violent extremism.

“You can’t arrest your way out of that so you have to develop a way that you can early intervene with some people. Disruption is really important.”

May Govt Admits ‘Significant Portion’ of Returned Islamic State Jihadists Going Unpunished https://t.co/IKVdAunzdk — Breitbart London (@BreitbartLondon) February 5, 2018

The Government has already admitted that a “significant portion” of the British jihadists who went to fight in Iraq and Syria are back in the country, and some recent attackers, including the Parson’s Green and Manchester bombers, were asylum seekers or from asylum seeker families.

Mr Wallace claimed officials would also be using immigration law to help prevent attacks.

“There are some people whose immigration status may be rightly examined to remove them from threat and there are people involved in normal crime who we could take off the streets,” he suggested.