Officials debate withholding Mandelson vetting documents from parliament

Exclusive: Opinions split on ‘unprecedented’ release of files, despite demand for ‘all papers’ related to ex-US ambassador’s appointment

• Revealed: Mandelson failed vetting but Foreign Office overruled decision

• Five key questions: Who overruled the decision to deny Mandelson security clearance?

Senior government officials have been considering whether to withhold from parliament sensitive documents that show Peter Mandelson had failed security vetting before he assumed the role of US ambassador, the Guardian can reveal.

Any such decision could amount to an extraordinary breach of a parliamentary vote which ordered the release of “all papers” relevant to Mandelson’s appointment.