By Ollie Stone-Lee BBC News Online political staff

It seems extraordinary that in the 21st Century the fact that a man is gay should make front page news - extraordinary, at least, if that man were not a senior Conservative.

There have, of course, been many homosexual Tory MPs in the past but, almost incredibly, Alan Duncan is the first to go public through his own free will with what was an open secret with friends and colleagues.

Tackling section 28 would reap much more benefits for the Tory party than many people realise

Ed Vaizey C-Change

Newspaper columnist Matthew Parris did, in fact, try to come out when he was a Conservative MP during a late night Commons debate.

The trouble was that nobody noticed and as he describes it, he went back in again content at least that his tentative words may have at least proved a way of communicating secretly with the party's chief whip.

Now Tory leader Iain Duncan Smith has welcomed Mr Duncan's statement in a low-key letter, stressing it will not affect the MP politically in the future.

Settling scores

The question, however, is not how it will affect Mr Duncan's politics - after all, his sexuality has been no secret to friends and colleagues.

Instead, all eyes will be on how Mr Duncan's decision could change the fortunes of a party rocked over the past week by renewed reports of infighting and unpleasantness over the removal of David Davis as Tory chairman.

Alan Duncan's friends and colleagues knew he was gay

Some modernisers anonymously accused Mr Davis of blocking attempts to make the party more inclusive to women, gay people and ethnic minorities.

Whether or not that really was the reason Mr Duncan Smith moved Mr Davis, it reignited talk of Tory divisions between "mods" and "rockers".

'No distractions'

In the last Parliament, that struggle between social liberals and social conservatives was epitomised by Michael Portillo, whose leadership hopes Mr Duncan backed, and Ann Widdecombe.

Ms Widdecombe on Monday argued her party should concentrate on attacking Labour rather than talking about "ideological purity".

Duncan Smith has agreed to review section 28 policy

Mr Duncan's statement appears more of a reflection of what Treasury spokesman John Bercow called a "changed mood" than something likely to herald any new dawn.

That appears to have come even since the claims of homophobia last summer against Michael Portillo, who had discussed his past gay experiences.

The party has already advocated giving some of the legal rights enjoyed by married couples to homosexual partners.

And openly gay Tory men have already been selected as candidates for the next general election.

Changing times

Michael Brown, the last Conservative MP to be "outed", had to resign after going on holiday with a gay 20-year-old when the age of consent was 21.

The tabloid headline then, in 1994, said "law maker is law breaker" but Mr Brown suspects Mr Duncan's move could if anything advance his career prospects.

The modernisers want more than just inclusive words.

Iain Duncan Smith apparently told Conservative gay rights activists that he does not like to use the word "straight" to describe heterosexuals since the opposite term, "bent", seemed perjorative towards gays.

This was seen as a sign of the Tory leader's anxiety to underline his inclusive approach.

Law test

The real test may come over calls for the Tories to abandon their past opposition to scrapping Clause 28 - the law preventing local councils from promoting homosexuality.

Ed Vaizey, of Conservative, modernising group C-Change, told BBC Radio 4's World This Weekend that such a reversal would show that Conservatives realise the UK has changed.

"Tackling that one issue would reap much more benefits for the Tory party than many people realise," he said.

Some Tory thinkers believe Section 28 is as near as Conservatives can get to a totem like Labour's Clause 4.

Alan Duncan's declaration may show change is under way but it is change on section 28 policy which could achieve his aim of banishing sexuality from political discussion.

That move really would mean victory for the mods over the rockers.