The three Liberal Democrat leadership contenders have welcomed the winner of last week's shock by-election victory over Labour to Parliament.
Willie Rennie overturned an 11,500 Labour majority
Willie Rennie, who overturned an 11,500 Labour majority in the Dunfermline and West Fife seat, was invested as the Lib Dems' 64th MP on Monday.
Party leadership candidates Sir Menzies Campbell, Simon Hughes and Chris Huhne posed for pictures with him.
All three camps said they had a chance of winning the contest.
Messages for rivals
Former Lib Dem leader Charles Kennedy, who resigned in January after admitting a drink problem, was also outside Parliament to greet Mr Rennie.
The party's former Scottish chief executive won Dunfermline and West Fife, the constituency where Chancellor Gordon Brown lives, by 1,800 votes.
Mr Rennie said: "The message to Gordon Brown is he can't take people up and down the country for granted any longer.
"People are fed up with too much spin and not enough delivery.
"There is also a message for the Conservatives, that nobody wants to go back to them."
Mr Rennie's investiture comes as voting by the 73,000 Lib Dem members for a new leader enters its second week.
The three camps all told the BBC News website they were confident.
A spokesman for Mr Hughes, the party's president, said members were "leaving it late" before casting their ballots and the response so far at hustings events had been "encouraging".
MP Martin Horwood, a backer of Mr Huhne, said the Treasury spokesman's campaign was "peaking" at the right time.
The example of David Cameron - a "dark horse" campaigner who went on to win the Conservative leadership last year - showed it was not vital to be "long-established" at Westminster, he added.
Meanwhile, a spokesman for acting leader Sir Menzies said he was "confident" about the campaign's position and that the remaining eight hustings would be important.
The new leader will be announced on 2 March, a day before the Lib Dem spring conference begins.