Ed Miliband has hit a setback in the race for pre-election celebrity endorsements, as formerly Labour-backing TV duo Ant and Dec revealed they may not vote for the party.
Meanwhile, interviewer Helen Rumbelow said that, in a comment which did not make it into the newspaper, McPartlin said he was "a real floating voter now".
The pair - winners of 27 National Television Awards for popularity and famous for shows stretching from Byker Grove in the 1990s to I'm A Celebrity ... Get Me Out Of Here! and Britain's Got Talent now - described themselves as "staunchly Labour" but said they did not know how they will vote on May 7.
Explaining his doubts about Miliband, Donnelly told the Times: "I'm not sure I could picture him as prime minister."
And McPartlin said: "I voted Labour all my life. But last election I voted Tory because I was thoroughly disillusioned with the Labour government.
"Now I'm thoroughly disillusioned with a coalition Government. I feel we're both staunchly Labour and would vote Labour if we could, but I don't know what their philosophy is any more."
Writing on Twitter, Rumbelow revealed: "Not in interview but Ant told me 'I'm looking forward to seeing their manifestos. I'm a real floating voter now'."