The men will appear at Westminster Magistrates' Court charged under the National Security Act.

Chi Leung (Peter) Wai, 38, Matthew Trickett, 37, and Chung Biu Yuen, 63, have each been charged with assisting a foreign intelligence service.

“While these offenses are concerning, I want to reassure the public that we do not believe there to be any wider threat to them," said Commander Dominic Murphy, Head of the Met's Counter Terrorism Command.

“This investigation remains ongoing, but now that charges have been brought, I urge people not to speculate or comment further in relation to this case."