By Nick Assinder
BBC News political correspondent
Simon Hughes' long-anticipated announcement that he is to run for leader of the Liberal Democrats has further ensured the party will face a fundamental choice of direction.
Mr Hughes, who lost to Charles Kennedy in 1999, has always been seen as a potential leader and, as he said himself, was last year confirmed as party president by the same electorate.
Hughes offers old Liberalism
He makes no bones about coming from the traditional, Liberal wing of the party, putting an emphasis on radicalism, civil liberties, public services and the environment.
Like all the other declared and likely candidates, he dismisses the left-right labels as out of date and wrong.
But he is unapologetic in his Liberalism, notably calling up the names of Lloyd George and Beveridge in his leadership announcement.
He even went so far as to promise "some bold steps and brave adventures" under his leadership, but was eager to stress his determination to bring the party together.
And that will be one of the big challenges facing all the would-be leaders which now include interim leader Sir Menzies Campbell, right-wing candidate Mark Oaten and likely contender from the so-called Orange Book wing, Chris Huhne, who is set to announce his leadership bid.
The Lib Dems are facing a real choice in the poll, but all the candidates who have so far declared claim they want to bring the two wings together and avoid splitting the party - one of Charles Kennedy's undoubted achievements.
That means finding common ground between those who support the right-wing, or Orange Book, agenda of free market economics, private provision in the NHS and less role for Europe and the more left-leaning social liberals like Mr Hughes.
Campbell has been seen as front runner
Inevitably the labels are loose and, for example, while Mr Oaten contributed to the Orange Book of essays and invented the term "tough liberalism", he was referring specifically to prisons policy.
On other issues such as ID cards, drugs and anti-terror laws, he has been more in line with Mr Hughes' thinking.
Sir Menzies has also shown a desire to avoid too-close an association with any group although he has attracted the support of some of the new, young, modernising MPs.
Mr Hughes, on the other hand, has a long record of social or traditional Liberalism and even been labelled - usually by his critics - as leader of the tax and spend wing of the party.
It has often been claimed he would push the Lib Dems further to the left, possibly onto the old Labour ground vacated by Tony Blair, particularly on public services.
But he probably knows he will have to accommodate the views of the newer intake of modernisers like Orange Book author David Laws unless he is ready for a knock-down, winner-takes-all approach.
Yet, at the moment, that appears to be a divisive and dangerous route no one wants to take.