The European Commission has warned Facebook, Google, YouTube, Twitter and other internet technology companies that they must do more to stem the spread of extremist content or face legislation.

Growing pressure from European governments has meant progress has been made by companies in significantly boosting their resources dedicated to help take down extremist content as quickly as possible.

But on Wednesday the EU security commissioner Julian King said: “We are not there yet. We are two years down the road of this journey: to reach our final destination we now need to speed up our work.”