Former News of the World editor Andy Coulson told the Old Bailey hacking trial that he regrets exposing David Blunkett's affair with Kimberly Fortier as he was accused of "pure hypocrisy" over the 2004 story.
During cross-examination by co-defendant Clive Goodman's lawyer, David Spens QC, the 46-year-old said the "irony" was not lost on him that he was being unfaithful to his own wife at the time.
Mr Coulson also conceded that reporter Neville Thurlbeck, who played him the former Home Secretary's voicemails in relation to the affair, had escaped disciplinary action and was not reported to the Press Complaints Commission.
He said he had never asked Mr Thurlbeck how he obtained the messages.
Mr Coulson denies one count of conspiring to hack phones and two counts of conspiring to commit misconduct in a public office.
More top news
Brendan Rodgers has been sacked by Liverpool after the 1-1 Merseyside derby draw with Everton
As the party says it represents the working public, thousands of anti-austerity demonstrators show they don't quite see it that way.
Alex Salmond found himself in a stand-off with airline staff after booking on to a flight under the name James Kirk.