The three contenders for the Liberal Democrat leadership appeared together in a special edition of BBC One's Question Time on Thursday, 9 February.
Sir Menzies Campbell, Simon Hughes and Chris Huhne all faced questions from the studio audience in an hour-long, unedited show.
"The timing of the programme is deliberate", said executive editor of Question Time Ric Bailey.
Ballot papers were only sent out to party members on Monday.
"There has been a great deal of interest in the revelations that have happened during the campaign", said Bailey.
"But not so much is known about policies and how each person's leadership would vary.
"So this is an opportunity for the members, as they receive their ballot papers, and the wider audience, to help them make up their minds."
The head-to-head leadership format was recently used by Question Time with Conservative contenders David Cameron and David Davis, in November 2005.
Following Charles Kennedy's resignation, more than 150 viewers sent messages via the Question Time website requesting a similar edition for the Liberal Democrats.
Thursday's programme used the same model as the Conservative debate, with the three contenders standing at a podium each.
Around half of the audience were Liberal Democrat supporters, with an even balance of loyalties towards each candidate as well as those who were undecided.
The other half of the audience was made up of a cross-section of persuasions from the whole political spectrum.
Ric Bailey added: "It can often feel as though the Liberal Democrats struggle to get the publicity they think they deserve, so this is a chance for the public at large and the membership to see the issues debated."
BBC One's Question Time is broadcast on Thursdays at 2235 GMT. It can also be watched live and on demand on the Question Time website.