Mr Darling says the prime minister wants him to stay in his job
Alistair Darling has told the BBC he has "absolutely no ambition" to be an interim Labour leader should Gordon Brown stand down after the election.
Speaking to the BBC's Campaign Straight Talk programme, he said he was "not interested in that at all".
Mr Darling also confirmed that should Labour win the election, Mr Brown had said he would remain as chancellor.
Asked if colleague Ed Balls wanted to replace him, he said: "I don't think Ed has got any intention to do that".
When interviewer Andrew Neil brought up the widely-reported speculation that Mr Balls - Secretary of State for Children, Schools and Families - had his eyes on becoming chancellor last year, Mr Darling replied: "There's nothing wrong with having ambition."
Mr Darling had earlier been asked what he thought were Labour's chances of winning on 6 May, and he admitted that the party was the "underdog".
But he said the last few days of the election would be critical, and that there had been elections in the past where the polls had not mirrored the final result.
Mr Darling said he hoped the electorate would "think long and hard" about the parties' records and where each planned to take the country in the future.
The chancellor also stood by his decision not to conduct a three year comprehensive spending review before the election, saying the continuing economic uncertainly would not have made it practical.
"I thought it would have been absolutely daft to have done a spending review," he said.
• Campaign Straight Talk with Andrew Neil will be broadcast on the BBC News Channel on Saturday, 1 May at 0130 BST, 0430 BST, and 2230 BST. It will also be shown on Sunday, 2 May at 0130 BST and 2230 BST, and on Tuesday 4 May at 0330 BST, also again all on the BBC News Chanel.