Six weeks of scandals will not destroy 150 years of Liberalism, Liberal Democrat leadership contender Sir Menzies Campbell has told activists.
Sir Menzies is currently the bookies favourite for the leadership
Speaking at hustings for the post, the acting leader dismissed those who had been "quick to write us off".
Lib Dem president Simon Hughes and contender Chris Huhne also took part in the hustings in Plymouth.
A week ago, home affairs spokesman Mark Oaten was forced to resign over claims of an affair with a male prostitute.
Mr Hughes also admitted he had had past gay relationships.
The leadership contest was sparked when the then leader, Charles Kennedy, resigned on 7 January after admitting he had been treated for a drink problem.
The new leader will be announced on 2 March after a party membership vote.
Also attending the Plymouth hustings was former Tory MP Sir Cyril Townsend, who announced he had defected to the Liberal Democrats last summer.
Sir Cyril Townsend, MP for Bexleyheath from 1974 to 1997, said he was only now revealing his departure from the Conservatives in a bid to boost Sir Menzies' leadership bid.
Sir Menzies told party activists: "Some critics have been quick to write us off but I have got a message for the writers of political obituaries.
"This movement has been fighting for liberalism for a century and a half - a great cause is not going to be destroyed in a month and a half."
He went on to outline plans to fight poverty and safeguard civil liberties as well as reducing the power of the state.
During his speech Mr Hughes made no reference to the party's or his troubles and focused on the local and regional aspects of the Lib Dems.
The Lib Dems are the biggest party in the region, having won all seats in Cornwall and three in Devon.
In his speech Mr Hughes focused on local agendas, affordable housing in rural areas, village schools and locally accountable police and local government.
Nominations for the party leadership closed on Wednesday
"These are core Liberal Democrat messages," he said. "If we do not keep communities in this country society disappears."
Mr Huhne said the party needed a radical increase in green taxes which would fund lower personal taxes to fight poverty in Britain.
In reference to the recent scandals Mr Huhne added: "What people do in the privacy of their own homes is their business not ours. I do not believe there is a role for a policeman in the bedrooms of the country."
Mr Hughes officially launched his campaign on Friday, insisting "the show goes on" despite admitting he had considered quitting the contest.
He insisted voters were more interested in policies than the private lives of politicians and said he was confident the party had the potential to "win big".
A YouGov poll for the Daily Telegraph on Friday showed support for the Lib Dems was down by 5% since December, to 13%.
The survey of 2,000 people was conducted before revelations about Mr Hughes' private life earlier this week.
Sir Menzies remains the bookies' favourite to succeed Mr Kennedy while Mr Huhne is in second place and Mr Hughes in third.
Saturday's hustings were the first of their kind since nominations for the party leadership closed on Wednesday.