Labour in Wales and Scotland could benefit in elections next year if Chancellor Gordon Brown succeeded Prime Minister Tony Blair beforehand, says Welsh First Minister Rhodri Morgan.
The assembly leader said if Mr Blair intended to stand down, he should do so before the assembly and Scottish parliament polls in May 2007.
However, he said he had no idea when Mr Blair was intending to quit.
Mr Morgan was speaking before the Wales Labour spring conference in Swansea.
He said: "If [Mr Blair] was thinking of going in the middle of 2007, then clearly it would make a lot of sense for him to go just before the assembly and Scottish elections.
"But if he isn't thinking of going next year, then that factor doesn't come into play.
'Cards close to chest'
He told journalists he had no idea when Mr Blair would leave his job, but added that Mr Brown, who is addressing the conference on Thursday evening, was "obviously hoping to take over the top job".
"Does [Mr Blair] want to beat Margaret Thatcher's record, or any other record? We just don't know," he said.
"He's playing his cards so close to his chest that I can't see them. Maybe he hasn't even had a look at them himself.
"It depends when he wants to go on the American lecture circuit or write his book."
He said new leader would enjoy a "honeymoon" period, which would be "advantageous for Labour and I'm sure he has thought of this, for him to go just before [the elections]."