Angela Rayner has ordered China to explain why it has redacted blueprints of a basement and other areas in a “mega-embassy” to be built in London.

Ms Rayner, who as Housing Secretary is tasked with deciding whether the project in the Royal Mint Court can go ahead, has given Beijing two weeks to explain why certain parts of its floor plans have been “greyed out”.

It comes amid fears the complex could effectively become a nest of espionage in the heart of London, with reports China could convert basement rooms into “spy dungeons”.

The demands from Ms Rayner are set out in an update from her department sent to DP9, the planning consultancy representing the Chinese embassy.

It suggests a possible change of tone in the Government’s approach to the project.