Senior officials at the heart of the row over the collapsed China spy trial will appear before a parliamentary committee next week.
The Joint Committee on the National Security Strategy will hold its first public evidence session on Monday, into prosecutors' decision to drop charges against Christopher Cash and Christopher Berry, who had been accused under the Official Secrets Act.
Both men deny any wrongdoing.
Among those giving evidence will be Stephen Parkinson, the director of public prosecutions; Matt Collins, the deputy national security adviser; Richard Hermer, the attorney general; Darren Jones, the chief secretary to the prime minister and Sir Chris Wormald, the cabinet secretary.
National Security Adviser Jonathan Powell, who has faced questions over possible political involvement in the case, will not attend the session but is expected to appear privately at a later date.
