Theresa May has ducked questions about whether Defence Secretary Gavin Williamson has told the full story of his fling with a junior colleague.
Mr Williamson stunned Westminster last week when he revealed details of a brief romance with a married colleague when he was managing director at a fireplace firm in 2004.
The defence secretary, who is a close ally of the Prime Minister, issued a statement to the Daily Mail last week in which described the 'profound impact' the romance had on his family.
In the following days he has declined to answer further questions about the incident, including the precise nature of his relationship with the unnamed woman and the exact circumstances in which he left the company shortly afterwards.
Theresa May (pictured in China today with her husband Philip) twice declined to say whether she was satisfied Gavin Williamson was telling the full story about his fling
Downing Street has declined to comment on the incident in detail, describing it as a 'private matter'.
Mrs May was also reluctant to be drawn on the matter today on her trip to Beijing when she was questioned about it for the first time.
Speaking to reporters on a visit to China, she twice declined to say whether she was satisfied Mr Williamson was telling the full story about the incident.
The Prime Minister dismissed suggestions that Mr Williamson could be investigated under the ministerial code for something that took place before he was a ministeras happened to her former deputy Damian Green.
She said: 'What has come out is something that happened even before Gavin was a member of Parliament, let alone a minister.
Gavin Williamson (pictured with his wife Joanne) stunned Westminster last week when he revealed details of a brief romance with a married colleague when he was managing director at a fireplace firm in 2004
'In relation to Damian Green, the report showed the ministerial code had been brokenit was on that basis that I took the decision.'
Asked again if she was satisfied Mr Williamson had told the full truth, she said: 'Gavin has told people about something that happened before he became an MP.'
Mr Williamson said last week that he had parted from his former employer on 'amicable terms', and friends have flatly denied claims he was subject to a disciplinary procedure.
One ally said the defence secretary was confident he had given an accurate account of the incident, adding: 'He knew there would be scrutiny. He's not stupid.'
But one senior Tory said the minister would be 'toast' if his story unravelled.