Labour Conference: David Miliband plays down leadership poll
David Miliband has played down an opinion poll suggesting voters would prefer him - rather than brother Ed - as Labour leader.
Asked about the survey, he said: "The grass always seems greener on the other side of the fence."
He said Ed - who beat him to the leadership in 2010 - was doing a "tough" job "very well".
A poll commissioned by the Tories suggested 65% of Labour supporters think David would make a better leader.
'Crash and burn'
Almost three-quarters (73%) of those questioned in the poll thought Ed Miliband did not have what it took to be prime minister in tough economic times, while almost as many (72%) saw him as too weak to be a credible leader.
Since losing the leadership election, David Miliband has spoken out about youth unemployment, become a non-executive director at Sunderland football club and starting teaching politics part-time at his old school in north London.
The former foreign secretary, who is in Manchester for the party's annual conference, was asked if he thought people would prefer him to be leader.
He replied: "Yes, but the most important thing to remember is that the grass always seems greener on the other side of the fence.
"I'm determined to do everything I can by supporting him (Ed)... sometimes that means speaking out, but it also means having the modesty sometimes to keep out of the way."
"Ed is doing a great job leading the party, leading with purpose, conviction, direction and what counts is the ideas that he's putting forward and the party's putting forward about how to change the country."
He later told a Progress fringe meeting he was "utterly focused on getting Ed into Downing Street".
The Daily Mail has reported that an updated version of a biography of Ed Miliband includes the revelation that his brother was overheard saying "Ed will crash and burn" as party leader, and claims the pair's relationship has deteriorated further since the leadership election.
David Miliband described the Mail story as "fiction" on Twitter.
It comes as Jack Straw, who backed David Miliband in the 2010 leadership race, criticised Ed's use of the term "predistribution" - improving wages for low paid workers - in a recent speech.
"He's got to come across to ordinary people," the former foreign secretary told BBC News.
"He needs to abandon some of the abstract language he uses. I knew what he meant when he talked about predistribution and it's a bright idea.
"If I stood on my soapbox in Blackburn talking about pre-distribution my audience would dissolve rapidly.
"There's a big idea behind it, that's about ensuring you deal with the causes of inequality rather then just the effects."
Ed is expected to use his keynote speech on Tuesday to talk about his own background and values in an attempt to make a connection with the public.