Nick Clegg has insisted he did not destroy the Liberal Democrats and claimed that quitting as leader before the general election would not have helped the party avoid its catastrophic defeat.
The former deputy prime minister said he does not regret going into coalition for "one millisecond" despite the near wipe-out at the polls.
Details have emerged of how Mr Clegg considered resigning last year after the party suffered heavy losses at European and local council elections.
He was quoted in The Guardian as telling one colleague: "If I believe - and I am very close to thinking it - I am the problem and not the solution, I have to stand to one side."
Asked on LBC about any plans to quit, he said: "I obviously would have done if I felt, as I said at the time, it would have helped the party.
"My own view is that changing leader a year before the election wouldn't have made much difference to, for instance, whether we would have been able to withstand Scottish nationalism north of the border."
Mr Clegg said the first thing he did when he saw the exit poll on election night was to "reach for a cigarette", despite quitting two and a half months earlier.
The MP said the party's drubbing had not been in his "worst fears" and he was "blindsided" by the result.
He told LBC: "I don't regret at all, not for one millisecond, doing the right thing for the country.
"I haven't destroyed the party. Liberalism will survive, the Liberal Democrats will bounce back."
Mr Clegg said he "totally" rejected suggestions the party did not reach out to former leader Charles Kennedy, who died earlier this month, after his defeat.
"Charles was an inveterate texter. He was always much better at texting than picking up his phone so I couldn't get hold of him on the phone, but we texted each other.
"He was actually amazingly resilient and was already thinking about how he would play a role in the European referendum campaign. He was very much looking forward."
Mr Clegg said fears about the SNP wielding power over a Labour minority government had "chilled the English heart" and led to voters turning towards the Conservatives.
The Sheffield Hallam MP had a brief discussion with David Cameron when they attended a VE anniversary ceremony at the Cenotaph in the hours after the result and got the "impression they were, much as we were, blindsided by the result, they were pretty gobsmacked to find themselves elected with an outright majority".
Despite their five-year working relationship, Mr Clegg said he will not continue to play tennis with the Prime Minister.
The Lib Dem said he has no plans to disappear in a "puff of smoke" but refused to commit to standing again at the next election.
Voters expected the party to "get a slap on the wrist", he said.
"They didn't expect that we would be thrown to the bottom of the stairs and they regret that," he added.