Politics LIVE: Keir Starmer to face Commons grilling over China at PMQs

Cabinet Secretary Chris Wormald is understood to have been prepared to publish a Government witness statement central to the withdrawal of espionage charges against the men.

Sources within the Government had claimed the Cabinet Secretary - the country's most senior civil servant - had gone to the CPS to discuss the publication of the witness statement by Matthew Collins, the deputy national security adviser.

It was that statement the CPS deemed did not meet the threshold for proceeding with the trial of the two alleged spies because it did not show China posed a threat to national security at the time the alleged offences occurred.

Prosecutors concluded during their meeting with Civil Service chief Mr Wormald that publishing the evidence outside of a courtroom would be "inappropriate", senior sources said.

But a CPS spokesperson denied the Government's claims.

"The statements were provided to us for the purpose of criminal proceedings which are now over," they said.

The spokesperson added: "The material contained in them is not ours, and it is a matter for the Government, independently of the CPS, to consider whether or not to make that material public."