Theresa May is set to order the internet to clamp down on extremism following the Parsons Green terror attack.
The Prime Minister is expected to urge web giants including Facebook, Microsoft, and Google to stop the likes of bomb-making manuals from appearing online.
Yesterday, 29 people were left injured after a bomb partially exploded on a District Line Tube in southwest London.
Mrs May will host a summit next week with French president Emmanuel Macron.
There, she will to speak out and warn online giants that more needs to be done to tackle extremists.
Police are still hunting for the suspect following the Parsons Green attack, and no arrests have been made.
Last night the UK terror threat level was raised from ‘severe’ to ‘critical’, as Isis claimed responsibility.
Police were called to the scene at around 8.15am after a device in a bucket exploded on a London Underground train.
The improvised explosive device detonated on the train during rush hour, when the service would have been at its busiest.
Police later launched a manhunt to find whoever left the bomb on the train which caused a fireball to rip through the carriage.
Images from the scene show wires coming out of a white bucket on fire inside an insulated Lidl bag towards the rear of the train.
Last night Prime Minister Theresa May announced the threat level had been changed.
She added that military personnel will replace police officers ‘on guard duties at certain protected sites which are not accessible to the public’.
Mrs May said: ‘The public will see more armed police on the transport network and on our streets, providing extra protection.
‘This is a proportionate and sensible step which will provide extra reassurance and protection while the investigation progresses.’
The prime minister added: ‘The Joint Terrorism Analysis Centre (JTAC) – that’s the independent organisation responsible for setting the threat level on the basis of available intelligence – has now decided to raise the national threat level from severe to critical.
This means that their assessment is that a further attack may be imminent.
‘Following JTAC’s decision, the police have asked for authorisation from the Secretary of State for Defence (Sir Michael Fallon) to enact part of the first phase of Operation Temperer. This is a well-established plan to provide military support to the police.’
The use of the military is believed to allow up to 5,000 troops to be deployed in support of the police.