Two titans of social media have been sternly warned they need to cooperate with an investigation over Russian interference in the EU Brexit referendum in 2016.
Twitter and Facebook have both been told they have until January 18 to cooperate with the select committee from the British Department of Culture, Media and Sport or face possible economic sanctions, The Guardian reports.
The committee was formed to look into "fake news" allegedly propagated through social media by Russian agents and has called the current level of cooperation "completely inadequate".
It is widely alleged the Kremlin used social media to push knowingly false stories in order to interfere with the results of the referendum, and both Facebook and Twitter have faced criticism for allegedly not screening their content sufficiently.
According to The Guardian, Damian Collins, head of the committee, wrote in a letter to Twitter last month: "The information you have now shared with us is completely inadequate. It seems odd that so far we have received more information about activities that have taken place on your platform from journalists and academics than from you."
Mr Collins said if they fail to comply, the committee will consider imposing sanctions, such as encouraging the advertising industry to withdraw business on "ethical" grounds.