Broadcaster Chris Tarrant and his wife Ingrid are to part, he has announced.
Chris Tarrant said he was to blame for the end of his marriage
Tarrant, 59, is best known for presenting ITV1 quiz show Who Wants To Be A Millionaire?
He said in a statement that he had only himself to blame for the collapse of his marriage, and appealed to the media for privacy.
There had been intense speculation about the couple's marriage after a series of stories had appeared in the media accusing Tarrant of an affair.
It had been reported that Tarrant left the family house in Esher, Surrey, three weeks ago after the allegations surfaced.
In his statement, Tarrant said: "I am deeply sorry for the hurt I have caused to my loyal wife and wonderful children, all of whom I adore.
"I have only myself to blame for the breakdown of my marriage.
"While the liaison which has led to all of this was not significant in my life, I will always regret the hurt and pain that I have caused to those whom I love.
"I now appeal to the media to leave us all alone to allow us to deal in private with what are intensely personal and private matters. There will be no further comment."
'Fair and civil manner'
Ingrid Tarrant released a statement on Tuesday, in which she said the couple's divorce would be conducted in "a fair and civil manner".
"Although I have had to absorb and adjust to Chris's betrayal, my children and step-children are just coming to terms with the overwhelming news.
"I urge everyone to respect their vulnerable position."
Mrs Tarrant, 51, said she had first become aware of her husband's affair several months ago, "and eventually gained positive proof from private investigators".
By the time the press began speculation about their relationship, the marriage was already over, she added.
The couple have recently appeared in a series of advertisements which portrayed Tarrant forgetting their anniversary and being forced to sleep on the couch.