These groups have become a platform for racism, misinformation, and support for criminal damage.

The groups contain Islamophobic attacks on London Mayor Sadiq Khan, white supremacist slogans, and antisemitic conspiracy theories.

Despite not explicitly stating that they were set up as part of a coordinated political campaign, the connection was uncovered by the investigation.

A report by Greenpeace's investigative unit, Unearthed, revealed that three closed Facebook groups with a total membership of 38,000 have been used for Islamophobic attacks against London Mayor Sadiq Khan.

Members have called him a "terrorist sympathizer" and a "khaki punt," and some have encouraged violence against him.

The groups also promote white supremacist slogans, antisemitic conspiracy theories, and encourage the destruction of Ulez enforcement cameras.

This is the latest controversy for the Labour Party regarding their campaigning tactics and attacks on Khan.

Previously, the party's former deputy chairman, Lee Anderson, was suspended for claiming "Islamists" were controlling the London mayor, and the Conservatives used a video of a panicked New York subway station crowd to claim Londoners were fearful of crime.

Senior Tory figures, including London mayoral candidate Susan Hall, have been active in several Facebook groups without disclosing their political affiliation.

The groups, which have the same administrators believed to be Conservative Campaign Headquarters (CCHQ) staffers and an activist, do not make it clear to members that they are linked to the Conservatives.

Susan Hall is a member of six groups and has posted in two, but did not respond to requests for comment.

The lack of transparency raises concerns.