Former foreign secretary looks unlikely to return to UK politics any time soon after applying to run the UN’s development arm

David Miliband, the former foreign secretary who was beaten to the Labour leadership by his brother Ed, is in the running for a high-profile job at the United Nations in New York, overseeing its international development work.

Some centrist Labour MPs still hold out hope that Miliband, who was MP for South Shields when he ran for the party leadership in 2010, might one day return, perhaps even as party leader.

But the Guardian understands he has put himself forward to run UNDP, the UN’s development arm, one of the most senior roles at the New York-based institution.

That suggests he has no intention of returning to frontline politics, or the UK, any time soon, and will continue to pursue a career in international development.

UNDP employs about 8,000 staff, according to the latest published figures, including many working on the frontline in some of the world’s poorest countries, and receives $4.5bn (£3.6bn) a year in donations from member states and charities.

Miliband has been running refugee charity the International Rescue Committee (IRC) since 2013, and had been tipped for a senior job in a Hillary Clinton administration if she had won the US presidential election.

UNDP’s current administrator, as its leader is known, is Helen Clark, the former New Zealand prime minister, who is due to complete a second four-year term in April, and is then expected to step down. She oversaw a significant streamlining of the organisation.

Clark was a contender to become secretary general of the UN, when António Guterres won the post last year. UN insiders say Guterres backs Miliband for the $170,000 (£135,000) a year role.

Miliband would be unlikely to secure the post without the backing of the UK government. A Whitehall source confirmed to the Guardian that Miliband had signalled he was keen to take on the job.

A spokesman for the IRC said Miliband would not comment on rumours about his future.

The Miliband brothers played out their sibling rivalry in public when both stood for the Labour leadership. David stepped down from parliament and began a new life on the other side of the Atlantic rather than serve in his younger brother’s frontbench team.

Since Labour suffered a humiliating defeat at the 2015 general election, and while it continues to languish in the polls, some of Jeremy Corbyn’s fiercest critics continue to suggest Labour members picked “the wrong Miliband”, and rumours periodically surface about the possible return of Ed’s elder brother.

David has been a trenchant critic of Donald Trump’s executive order on refugees in recent days, telling the Guardian it threatened the west’s reputation for compassion: “When you meet families that are being torn apart by this ban, that causes doubt about what our countries stand for, and that is one of the most dangerous aspects of this.”