Conservative justice minister Crispin Blunt has revealed he is gay and is separating from his wife.
The Reigate MP appealed for privacy and said he was "coming to terms with his homosexuality".
In a statement, his office said: "Crispin Blunt wishes to make it known that he has separated from his wife Victoria.
"He decided to come to terms with his homosexuality and explained the position to his family. The consequence is this separation.
"There is no third party involvement, but this is difficult for his immediate and wider family and he hopes for understanding and support for them.
"The family do not wish to make any further public comment and hope that their privacy will be respected as they deal with these difficult private issues."
Blunt recently hit the headlines when his proposal that the ban on prisoners holding parties and other social occasions was overruled by Downing Street.
Elected to Parliament in 1997, he was little known outside Westminster until his bombshell on the night of the local elections in May 2003, when he suddenly resigned from the Opposition front bench, calling for the replacement of his leader Iain Duncan Smith.
He later revealed that he had in fact voted for him in the ballot with Kenneth Clarke two years earlier.
Blunt is the second coalition minister to reveal he is gay since the election with former chief secretary to the Treasury David Laws' sexuality being revealed following newspaper reports about his parliamentary expenses claims.