A post shared on social media purporting to show the mayor of London saying pro-Palestinian marches should take priority over Armistice Day events is fake and police are investigating, a spokesman for the mayor has said, Reuters reports.

The social media clip could further inflame tensions in the capital, a day before a large pro-Palestinian march is planned to coincide with the anniversary of the end of World War One. Prime Minister Rishi Sunak has called the march “provocative”.

There are fears there could be violent confrontations as far-right groups have indicated they will protect the Cenotaph war memorial on Saturday, Armistice Day.

A spokesperson for London Mayor Sadiq Khan, a member of Britain’s Labour Party, said of the social media post: “The Met (London’s Police) and their counter-terror experts are aware of this fake video that is being circulated and amplified on social media by far-right groups, and are actively investigating.”

The Met did not immediately respond to a Reuters request for comment.