John Bercow, the Speaker of the House of Commons, is poised to announce that he is to divorce his wife Sally over her alleged affair with his cousin.
A friend of the family indicated he is likely to make a public statement in the next few days in an effort to draw a veil over the painful chapter, which has overshadowed his public role.
It comes as Mr Bercow (52) is expected to finally see off attempts to unseat him as Speaker with MPs voting to re-confirm him in the role as the new Parliament meets formally for the first time today.
MPs are set to re-elect Mr Bercow in the role despite hostility between him and the Tories which culminated in a failed attempt before the general election to oust him by changing parliamentary rules.
David Cameron is said to have told Tory MPs they now have more important priorities than removing the Speaker.
Mr Bercow's marriage has been a constant source of attention throughout his six-year tenure in the role, with his wife becoming a household name after posing for a photo-shoot in Speaker's House draped in a sheet and appearing on Celebrity Big Brother.
Allegations that she had been having an affair with her husband's cousin Alan Bercow emerged last week.
Mrs Bercow said last week that her husband was a "very forgiving" man, but added: "I'm not sure I want to be forgiven."
She has been living at their mews house in Battersea, south London, while her husband remained at Speaker's House, his grace-and-favour flat in Parliament, with their three children.
Speaking after details of the alleged affair became public, Sally Bercow described herself as a "terrible wife".
Appearing without her wedding ring on she admitted she has had "a difficult marriage for a long time, primarily because we're living in Parliament and I hate it there".
She added that Alan Bercow had left her "f***ing heartbroken". (© Daily Telegraph, London)