Home Secretary John Reid has refused to rule out a leadership challenge when Tony Blair steps down as Prime Minister.
Mr Reid said that he would make his intentions known after Mr Blair sets out his plans for leaving No 10 next week.
"Once we know this election and we are into the stage at which Tony Blair said he is stepping down, and he has now said that, then I will make my views known," he told BBC Radio 4's The World At One.
Mr Reid had previously appeared to rule out a challenge to Chancellor Gordon Brown - Mr Blair's expected successor - saying he expected to see "a coming together of all of the Labour leadership" following this week's elections.
However his latest comments prompted bookmakers William Hill to cut the odds on him becoming the next Prime Minister from 25/1 to 16/1.
With key Blairite ministers now lining up to endorse Mr Brown, many Labour MPs now believe that there is a remote prospect of a heavyweight challenge from within the Cabinet.
But if the results for Labour in Scotland - long regarded as Mr Brown's political fiefdom - are worse than expected, someone like Mr Reid may be tempted to throw down the gauntlet to the Chancellor.
