THE battle for the Liberal Democrat leadership came to life yesterday when Mark Oaten threw his hat in the ring and promptly landed his first blow against Sir Menzies Campbell, the frontrunner.
In a swipe at 64-year-old Sir Menzies, the party's home affairs spokesman stressed his credentials as the candidate with "vigour" and "energy".
Mr Oaten, 41, is believed to have the backing of Charles Kennedy and is set to capitalise on the anger of activists at the ousting of their leader.
By announcing his candidacy yesterday, Mr Oaten also stole a march on Simon Hughes, the party president, who is likely to mount a serious challenge to Sir Menzies by appealing to the rank-and-file members, who have a major say in the outcome.
Mr Oaten set out his libertarian vision for the party while stressing that it needed a leader for the long term - a clear dig at Sir Menzies, who will be nearing 70 at the next election.
"I am up for this challenge. I believe I have the energy and the vision to lead this party," he said.
Although he stressed that he wanted to fight a positive campaign and that he had "great respect" for Sir Menzies, Mr Oaten also emphasised his advantage in being able to take the party into the future.
"I am delighted he is acting leader at the moment. He is a statesman, well regarded by the public, well regarded by the party," Mr Oaten said.
However, he added: "We need long-term politics. This is about getting us into power and I'm determined this party does it and it has a proper debate, a proper agenda about how we achieve that and that is what I'm determined to do in the months and the years ahead."
Doubts were raised as to whether Mr Oaten had the nominations of the requisite seven MPs after his aides refused to name his supporters.
They said this was for "strategic" reasons, as they wanted to keep the names from the competition and drip-feed them to the press to prolong the publicity for the campaign.
However, The Scotsman understands their strategy could be to borrow or share supporters with other candidates.
Under Liberal Democrat rules, MPs can sign the nomination forms of more than one contender.
While Mr Oaten is ranked third favourite, with bookies giving odds of 5-1, his entry into the race could be privately welcomed by Sir Menzies's supporters.
While many of his natural allies on the modernising wing have backed Sir Menzies, the outcome they would fear the most is a victory by Mr Hughes, who they believe would steer the party's economic policy to the left.
Mr Oaten set out his views on tax yesterday, calling for the threshold for the Lib Dems' proposed 50 per cent tax rate to be raised from 100,000 to 150,000. He also suggested the income at which a household should pay local income tax should be increased from 42,000.
He further dismissed David Cameron's Conservatives as having "fake" liberal credentials. His attack will be welcomed by activists and some MPs, who felt that Mr Kennedy had failed to challenge the resurgent Tory party, which had started to make overtures to wavering Lib Dem supporters.
Mr Hughes is expected to announce his candidacy over the next week, after the bookmaker William Hill took a 1,000 bet on him winning the race.
The Lib Dems yesterday suffered a double blow when a poll put the party's support at its lowest since 2001 and Michael Brown, the businessman who gave them 2.4 million before the last election, said he was "99.99 per cent" certain he would not give the party any more after Mr Kennedy's sacking.
Mr Oaten's supporters hope he will change his mind.