Simon Hughes says when he entered politics in 1980, the climate was less gay-friendly. So what's changed?
Laws have changed. Have attitudes?
Modern audiences watching the film Brokeback Mountain see a vivid representation of sexual repression and homophobia in the rural US from the 1960s to the 1980s.
Society has moved into more tolerant waters since then, but recent political events in the UK suggest public figures are still inhibited from being entirely honest about their sex lives.
Liberal Democrat Mark Oaten resigned from the party's front bench after a newspaper claimed he had an affair with a male prostitute. His secrecy can be partly explained by the fact he is a married father-of-two.
But the experience of his party colleague Simon Hughes, who is not married, suggests wider social pressures are still at work. Having denied in the past that he was gay, he admitted on Thursday having had same-sex relationships.
Mr Hughes apologised, saying he had not lied because he considers himself bisexual. And when he entered public office in 1980, he said, he decided to keep his private life private.
"But there comes a time when it isn't sustainable," he said. "I hope that for those listening and for other people in 2006 and beyond, they won't have to make the choice I did and I hope that these issues won't be as difficult in years to come."
So have Westminster and the society it represents changed enough for secret lives to become a thing of the past?
Reflecting the progress of the wider world, the political world has moved on in the 21 years since Chris Smith, now Lord Smith, became the first openly gay MP.
As secretary of state for national heritage, he became the first "out" minister in 1997. At the same election, openly gay MPs Ben Bradshaw and Stephen Twigg also won seats, and months later, MP Angela Eagle came out.
Conservative MP Alan Duncan was the first in his party to voluntarily declare he was gay in 2002, and increased his majority in Rutland and Melton at the next election, which suggested that in some areas at least, being gay was no hindrance at the ballot box.
But not all gay MPs had an easy ride. Agricultural Secretary Nick Brown was forced to make a statement in 1998 after enquiries by newspapers. It was a reluctant step, he said, because he did not want to upset his elderly and sick mother.
Stephen Williams became the first openly gay Liberal Democrat MP when elected last year in Bristol. He says although society and politics are becoming more tolerant, there's still some way to go.
WESTMINSTER'S GAY HISTORY
1984: Chris Smith first openly gay MP
May 1997: Smith is a minister, two more gay MPs
Sep 1997: Angela Eagle first lesbian MP
1998: Waheed Alli, 34, first gay peer
2002: Tory Alan Duncan comes out
2005: Lib Dem Stephen Williams elected
"I do think there are plenty of people, even my generation, and younger who, depending on their personal background, still find coming out difficult. Although society has made huge advances in the last 10 years, we still don't have a fully liberal, open society."
The number of openly gay MPs will rise, he says, but there can be a political cost, as he discovered in the 2001 election. During that campaign, he received nasty letters and phone calls, while people canvassing on his behalf were told on doorsteps that there would be no votes for a "queer".
It's an experience he calls upsetting but not hugely damaging. Indeed in 2005, in the same seat, there was no abuse, which he thinks reflects a more enlightened climate.
But for MPs elected some time ago, it can be difficult to suddenly be honest in later life, he says. Every gay man is questioned about his sexuality before he's ready to answer truthfully.
"Although I didn't directly lie about it, I found a form of words to disguise the fact I was gay by saying I hadn't found the right woman or 'Who would want to go out with me?'
"Until you're ready to do it, and every gay man reaches a different decision about when is the right time, you will always find a form of words to enable you to get through the day, not take personal abuse and to carry on with your job."
Mr Hughes' successful Parliamentary campaign in 1983 was tinged with accusations of homophobia, but the victim was gay Labour candidate Peter Tatchell, in a bitter by-election battle in Bermondsey.
The Liberal Democrats presented their candidate as the "straight choice" and Mr Hughes later apologised for any offence the campaign may have caused.
Now his former opponent Mr Tatchell praises his record on gay issues but says the revelation about his past suggests bigotry remains in Parliament and in the constituencies.
"Both these exposes [Oaten and Hughes] and the media coverage of them have shown - although we have progressed, no doubt about that - there's still a whiff of homophobia around Westminster. Most lesbian and gay MPs are still not open about it."
He estimates there should be about 65, which means at least 50 are hiding their sexuality or leading double lives.
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