Mandelson blamed for losing election

In the first indication of a backlash against the former business secretary over his memoirs, Charlie Whelan said Lord Mandelson had run the worst election campaign "in Labour's history".

Mr Whelan, political director of the Unite union, is a former Press secretary to Mr Brown.

His intervention came after Lord Mandelson, in an interview to promote his new book, said Mr Brown was "very badly served" by his aides and their "unbridled contempt" for Tony Blair.

Mr Whelan hit back, saying: "Peter ran the worst general election campaign in Labour's history. Nobody knew what the message was at all. It was a disaster from beginning to end."

He added: "Peter wasn't focused on the campaign at all. Clearly his only thoughts were for his book."

There are concerns in Labour circles about potential for the book, The Third Man, to highlight again the divisions and feuds at the top of the former Labour government. His memoir is being published more than a month ahead of Mr Blair's long-awaited autobiography and the former prime minister is said to be annoyed at the timing.