If the platforms fail to improve their record by year-end, the Commission has said it may introduce “regulatory or co-regulatory measures”, which could force tech companies to share their data more openly.

This would allow journalists, developers and the research community to carry out analysis of disinformation operations.

The UK Electoral Commission has also called for new electoral regulatory rules to ensure proper oversight and controls.

The Open Knowledge Foundation has been campaigning to clamp down on the spread of disinformation on Facebook and other social media sites.

Catherine Stihler, chief executive of the Open Knowledge Foundation, said: “Facebook, Google and Twitter must act on the growing demands for greater transparency.

“The social media giants have been at the centre of a series of rows about disinformation, particularly in connection with the Brexit referendum, and that simply cannot be allowed to happen once again in the run-up to December’s UK General Election.

“Urgent action is required, and if the platforms don’t act, then they need to be forced to.

“The institutions of the EU must use their influence to require online platforms to provide more detailed information allowing the identification of malign actors, put pressure on Facebook, Google and Twitter to increase transparency, and encourage closer working with fact checkers to prevent the spread of disinformation.

“The best way to tackle disinformation is to make information open, allowing journalists, developers and the research community to carry out analysis of disinformation operations.”