Lib Dems should not just pick a "safe pair of hands", leadership hopeful Simon Hughes has said in an apparent dig at rival Sir Menzies Campbell.
Mr Hughes said the party should not choose a 'safe pair of hands'
Mr Hughes urged party members to choose a leader who could "reach out" to new supporters, not just "steady the ship".
The party's Treasury spokesman Chris Huhne unveiled his leadership manifesto on Friday.
Mr Huhne says he has "the ideas to set the pace" and will call for a "radical decentralisation" of power.
Mr Huhne is stressing his commitment to the environment and social policy by launching his manifesto at workshop in west London where unemployed and disabled people refurbish unwanted office furniture for community groups.
The document, entitled Ideas, Leadership, Experience, will portray Mr Huhne as a "bridge to the future".
Ahead of the launch, Mr Huhne said: "Liberalism is the last of the great systems of values and ideas, as relevant today as ever because it puts the individual at the heart of politics.
"Our society needs to operate on a human scale, where voters who experience for themselves public services can hold decision-makers to account: booting them out if they fail, and rewarding them if they succeed.
"Competition works in politics, just as it works in economics."
The leadership contest has been blighted by stories about the private lives of senior Lib Dems.
Charles Kennedy was ousted as leader after admitting a drink problem, Mark Oaten quit the front bench when his affair with a male prostitute was revealed.
And Mr Hughes apologised for misleading people by denying he was gay, saying he had previously had relationships with both men and women.
The Bermondsey and North Southwark MP told BBC Radio 4's Today programme on Friday: "I never intended or wanted to deceive.
"It has been dealt with. I made a very clear statement last week and I believe I can move on and the party can move on.
"There will be no deceit and I can with confidence know that I can lead the party to be a campaigning party telling the truth to British voters."
Sir Menzies, 64, has taken over from Mr Hughes as bookmakers' favourite in the leadership race.
But Mr Hughes appealed to the 73,000 Lib Dem members, saying: "I just urge them not to go for the 'safe pair of hands' option, not to go for the 'steady the ship' option - to go for the reaching out option."
He also said the party needed to be clearer on foreign policy, the brief held by Sir Menzies.
"We must hold to our line that we must come out of Iraq at the end of the year," he said. "That is what we said, that is what we must hold to."
Mr Huhne too has said it would be counterproductive to keep British troops in Iraq beyond the end of this year.