Foreign Secretary William Hague said today his decision to publicly deny speculation about a gay affair with an aide was "not an easy thing to do".
Revealing the frustration he felt, Mr Hague said he and his wife Ffion had "had enough" and decided to "put the record straight" about the rumours which had been circulating, particularly on internet sites.
Downing Street said that Mr Hague continued to enjoy the "100% support" of Prime Minister David Cameron.
In a frank statement issued yesterday Mr Hague denied having had an "improper" relationship with special adviser Christopher Myers and insisted his marriage was secure.
He also revealed that his wife, Ffion, had suffered a number of miscarriages as they tried to start a family.
Mr Myers quit his post as special adviser, citing the pressure put on his family by media inquiries into the allegations.
In a press conference at the Foreign Office, Mr Hague said his former aide was "someone who is rather fed up of the political world, and who can blame him?".
Mr Myers told Sky News he "categorically denied" the allegations about an improper relationship with Mr Hague.
The Foreign Secretary insisted he had no more to add to his statement yesterday, but gave an insight into why he and Ffion had decided to go public.
"Yesterday, I made a very personal statement, which was not an easy thing to do. I am not going to expand on that today.
"My wife and I really felt we had had enough of the circulation of untrue allegations, particularly on the internet, and at some point you have to speak out about that and put the record straight."
Questions about his private life dominated the joint press conference held with Mr Hague's German counterpart Guido Westerwelle.
Mr Hague insisted that the work of the Foreign Office "had not missed a beat at any stage" despite the rumours circulating about him.
A spokeswoman for the Prime Minister said that Mr Cameron was not making any new statement on the issue but had given the Foreign Secretary his full backing throughout.
The spokeswoman said: "We have always given William our 100% support. That was the case yesterday and it is the case today.
"The Prime Minister totally understands why William made the statement he did and he backs him 100%."
There was also support from the chairman of the Conservative Association in Mr Hague's North Yorkshire constituency of Richmond.
Christopher Bourne-Arton told BBC Radio 4's The World At One: "It was a very brave statement. I am only sorry it was necessary."
Mr Myers, 25, was employed by Mr Hague during the general election campaign as a constituency aide and had worked for the Foreign Secretary as a policy adviser on a salary reported to be £30,000.
Mr Hague admitted to "occasionally" sharing hotel rooms with Mr Myers during the election.
But he added: "Neither of us would have done so if we had thought that it in any way meant or implied something else.
"In hindsight, I should have given greater consideration to what might have been made of that, but this is in itself no justification for allegations of this kind, which are untrue and deeply distressing to me, to Ffion and to Christopher."
Mr Hague's decision to share a room with Mr Myers led some senior Westminster figures to question his judgment.
Former Tory cabinet minister John Redwood wrote on his blog that the Foreign Secretary "now seems to understand it was poor judgment to share a room with an assistant".
Labour leadership contender Ed Balls said: "I've never shared a room with an assistant of mine, male or female, and I think probably when you are in a senior position you have got to be careful with these things."
During an interview with BBC Radio 2's Jeremy Vine, Mr Balls also doubted the wisdom of Mr Hague's statement: "I'm not sure whether going out and making a public statement in that detail is the wisest thing to do.
"I think it probably gives more credibility to some of these websites and to allegations which aren't true."