“The information from the Security Service today is extremely serious. We condemn in the strongest terms the attempts by China to interfere in Britain’s democratic processes.

“We are seeking further information and briefing from the Home Office and MI5 on their assessment of the extent of the deception and interference and the ongoing risks of malign activity from foreign states.

“We are also asking the Government to ensure that all parliamentarians and political parties are given revised information from the Security Service on the security risks and measures to guard against any threat of interference in our democracy or national security.”