Former Foreign Secretary David Miliband has criticised his brother Ed’s leadership of the Labour Party.
He told the BBC Labour had lost the general election because voters “did not want what was being offered”.
The leadership had allowed itself to be portrayed as “moving backwards”, he said.
But Mr Miliband, who was beaten to the job of leader by his younger sibling in 2010, also said the two of them would “remain brothers for life”.
He also ruled himself out of becoming the party’s next leader, which would not be possible as he is not an MP.
Mr Miliband quit parliament in 2013 to work for the International Rescue Committee charity in New York.
Speaking to the BBC’s Nick Bryant in New York, he said: “I’m clearly not a candidate in this leadership election… the commitment I have to the job I’ve got doesn’t change.”
Ed Miliband resigned as Labour leader in the aftermath of the general election, which left his party on 232 seats, with the Conservatives securing an overall majority.
David Miliband (R) left UK politics after losing the Labour leadership battle to his brother
His approach was criticised at the weekend by former Business Secretary Lord Mandelson, while some of the MPs tipped to replace him have spoken of the need to appeal to “aspirational” voters.
David Miliband said there was “absolutely no point in blaming the electorate” for the election result.
“They didn’t want what was being offered,” he added.
He said his brother and former Labour Prime Minister Gordon Brown had “allowed themselves to be portrayed as moving backwards from the principles of aspiration and inclusion that are the absolute heart of any successful progressive political project”.
He added: “Either we build on what Labour achieved after 1997 and we have a chance to succeed, or we abandon it and we fail.”
But he said he remained in touch with his younger brother, adding that “many of the attacks on Ed were unpleasant and unfair and I think he dealt with them with enormous dignity and with courage… I’ve always said you remain brothers for life and that’s something that has to be kept”.
Asked whether would be better off if he had been chosen as leaders, Mr Miliband said there was “no point in trying to press the rewind button in life”.
BBC political correspondent Iain Watson said Mr Miliband’s remarks about aspiration suggested he thought the leadership was “obsessed with taking money from those at the top” but that it “didn’t have enough to say about those in the middle”.