Ed Miliband today launched his bid to succeed Gordon Brown as Labour leader as he joked that he wanted the contest to be 'fraternal'.
The former Energy Secretary described his older brother David as his 'best friend' and insisted there would be no bitterness as they battle for the top job.
David, 44, the former Foreign Secretary, is the front runner to win the post but Ed, 40, is regarded as the dark horse of the competition.
He insisted today: 'David is my best friend in the world. I love him dearly and I think it is absolutely possible and necessary for this party to have a civilised contest.
"There is no way I'm going to take lumps out of him either on the record, off the record or behind the scenes. It is not my way of doing politics, but I'm certainly not going to do it to my brother and nor is he.'I'm in it to win it, but win or lose we will remain the best of friends and I will still love him dearly.'
Ed Miliband used to work under Mr Brown at the Treasury. David, meanwhile, is Tony Blair's protege and is believed to have Lord Mandelson's support.
Ed Miliband declared his candidacy in a keynote speech to the Fabian Society, in which he condemned his party's failure to clamp down on greedy bankers.
The former Cabinet minister also admitted that Labour lost its 'radical edge' while in Government.
His comments will be seen as a direct appeal to the Left-wing activists and unions ahead of the forthcoming leadership contest.