Andy Burnham is on course to become Labour’s new leader, as the only declared candidate ahead of nominations for the contest opening on Thursday.
Al Carns, who was thought to be the final remaining potential challenger to the former Greater Manchester mayor, ruled himself out of the running for the leadership on Wednesday evening.
Mr Carns, a former armed forces minister, said: “I’d hoped a leadership contest would give us the opportunity for a proper debate.
“But months of internal Labour politics isn’t what the country needs right now. We’ve got to get on with the job. Andy Burnham’s earned this and he’s got my full backing.”
Prospective candidates need the backing of 81 MPs to put themselves forward to replace Sir Keir Starmer, who resigned in June under increasing pressure from his party.
In the absence of any other candidates, Mr Burnham will be formally declared Labour leader at a special conference on 17 July and is expected to then become prime minister on 20 July.
The Makerfield MP will still take part in an online hustings with Labour MPs on Monday evening, even if he is the only one in the running.
Writing in The Times, Mr Burnham said he would seek stability in his foreign policy as prime minister as he set out his commitment to Nato, the nuclear deterrent, maintaining close ties with the US and support for Ukraine as well as continuing to bolster relations with the EU.
Sir Keir’s national security adviser Jonathan Powell will be kept on in the role, he said.
The boost to defence spending set out in Sir Keir’s defence investment plan should be used to back British businesses and economic growth with a focus on inward investment, he said.
He also said he was committed to “levelling with” the public over spending decisions.
He added: “I want to be more open with the public about how and where defence funding is spent.
“For our biggest defence and infrastructure projects, I want to see more detailed, public progress updates, with more transparency and accountability to tackle cost overruns or delays before they spiral out of control. Our increased investment must be combined with an increase in scrutiny.”
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