As the London Mayor started to speak at today’s event, the protesters stood up and shouted that they were making a ‘citizen’s arrest’.

The men – who got into the event by buying tickets – also vowed to take the panel’s chair Kate Green MP into custody as well as Sir Keir Starmer and general secretary Andrew Harrop.

They then told guards that they were attempting to arrest the politicians under ‘common law jurisdiction’ and the Magna Carta – the 13th-century document that is often regarded as the foundation of the modern legal system.