Lord Razzall has quit his role as the Liberal Democrats' election mastermind saying he wants a change.
The Lib Dem peer is a close friend of Charles Kennedy
The party confirmed that Lord Razzall, chairman of the campaigns and communications committee for the past two polls, has stepped down.
A spokesman said the peer - a friend of Charles Kennedy - wanted his successor to have time to settle into the job.
Nominations for his replacement close on 22 June. Lib Dem MP Ed Davey is expected to be a key contender.
Mr Kennedy quit as Lib Dem leader in January after admitting to a drink problem.
Sir Menzies Campbell won the ensuing leadership contest, beating off challenges from Chris Huhne and Simon Hughes.
Sir Menzies has asked trade spokesman Mr Davey to look at the issue of campaigning.
He has just returned from a fact-finding trip to North America to look at the techniques of US Democrats and Canadian Liberals.
Lord Razzall was Charles Kennedy's best man when he married Sarah Gurling in July 2002.