Home Secretary Amber Rudd has summoned Google, Twitter and Facebook bosses to a meeting over online extremism, hinting that a new counter-terrorism strategy will incorporate proposals to enforce the speedier removal of hate videos.

And in the wake of the Westminster terror attack, Foreign Secretary Boris Johnson has joined the condemnation of web companies which run advertisements alongside extremist videos, saying: "They need to stop making money out of prurient violent material.”

Ms Rudd writes in the Telegraph: “Each attack confirms again the role the internet is playing in serving as a conduit, inciting and inspiring ­violence, and spreading extremist ­ideology of all kinds.

 “We need the help of social media ­companies: the Googles, the Twitters, the Facebooks, of this world. 

“And the smaller ones, too – ­platforms like Telegram, Wordpress and Justpaste.it” 

The latter trio may not be widely known, but are facing similar challenges to the main players.

Telegram's messaging service has 100 million active monthly users. Wordpress is a website publishing and hosting ­system. JustPaste.it ­allows users to upload text, images and video.

A "furious" Mr Johnson accused internet companies of failing to remove terrorist propaganda, even when it was brought to their attention.

The Community Security Trust this week criticised Google after the company said it would remove adverts from antisemitic and extremist content hosted on its YouTube platform — while failing to take down the offensive material itself.

More than 250 brands — Tesco, Marks & Spencer and Toyota among them — have pulled their advertising because of Google’s failure to prevent its platforms from being flooded by extremist content from hate preachers, rape apologists and homophobic extremists banned from the UK.

Google Europe has apologised but said it has no plans to employ extra staff to search for and delete extremist content.