Writing in the Guardian on Friday, Ashdown attacked "short-term personal manoeuvring" by some of his colleagues who wanted to see Clegg ousted from power.
"The right thing for Liberal Democrats to do now is to continue to do what we have done so well so far. Concentrate on the job we set our hands to under Clegg's leadership. Nothing else," he said.
His comments came after Lib Dem peer Lord Oakeshott, a close ally of business secretary Vince Cable, said the deputy prime minister should be removed as party leader to avoid electoral oblivion at the next election.
Lord Ashdown praised Clegg for taking the Lib Dems into government. "I failed; Nick has succeeded," he said.
"In my view he has led our party in government, not flawlessly of course, but with a skill no one else in British politics could have matched and a grace under fire that should make us proud."
And he said Lord Oakeshott had only been given time to speak out because it was the august 'silly season'. "All party dissidents, minor or not, suddenly find themselves welcome on every front page and in every news studio," he said.
In response to Lord Oakeshott's attack, Clegg made it clear that he had no intention of quitting insisting he was "going to lead this party through the next general election and beyond".
And while there does not appear to be a serious threat to Clegg's position at the moment, the Daily Telegraph reports that David Cameron is increasingly concernedabout the threat posed by a leadership challenge from the more left-wing Vince Cable.
According to the paper a "well-placed source" close to the prime minister said: “We need to protect Nick and Danny [Alexander], probably the two most right of centre Liberals for the last 25 years. We can’t have them thrown out".