Kemi Badenoch’s Conservative Party has been pressing ministers over their handling of the collapsed trial of Christopher Cash, a former parliamentary researcher, and Christopher Berry, a teacher.

Both men, who deny wrongdoing, had been accused of passing secrets to China, but charges against them were dropped last month.

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.