Social-media giants Facebook and Twitter have been given until January 18 to turn over information related to allegations of Russian interference in Britain's 2016 referendum on leaving the European Union.
Damian Collins, chairman of the British Parliament's culture and media committee, said on December 29: "It's been over a month since we made the request to Facebook for this information and we need to see some action."
"We have had similar issues with Twitter, and we have gone back to them and asked them for deeper investigations," he added.
He did not specify what action would be taken if the companies do not comply, but he said that "if you ignore requests to act, if you fail to police the site effectively and deal with highly problematic content, then there has to be some sort of sanction against you."
Collins has requested that Facebook conduct a comprehensive search for "any adverts and pages paid for or set up by Russian-linked accounts" that were active before and during the June 23, 2016, Brexit vote, which passed by a narrow margin.
Researchers have said a St. Petersburg-based organization called the Internet Research Agency employs hundreds of people to post content on socially divisive issues on social media in what appears to be a Kremlin strategy to foment discord in the West.
Facebook and Twitter did not respond to requests for a comment on Collins’s remarks, but Facebook previously denied it was not cooperating with Collins, saying it took his requests "very seriously."