"I will remain in this position by 2027," Starmer declared, adding that if our conversation went well, he might welcome us into Downing Street for another conversation next year.
There is never truly downtime for leaders. Just an hour before our chat started, the PM had been in calls with Ukrainian President Volodymyr Zelensky and working to understand precisely had happened in Venezuela, where his close ally, US President Donald Trump, had just launched a strike against and detained its leader, Nicolás Maduro.
Once our interview, which was considerably lengthier than typical, had ended, Maduro had been indicted in New York.
As the new year begins, the Prime Minister seems to have had something of a reboot. Perhaps even just a bit of a rest with loved ones at Chequers, the prime minister's rural getaway.
That certainly appeared to have left him in improved morale than at the difficult end of 2025, a awful political year for him.
But are he and his allies deluding themselves if they think his fortunes are about to get better?
The uncomfortable truth for the leader is that many of his colleagues are convinced he's ineffective at his job. A faction of them would rather take a risk and get him out in 2026.
But Starmer was having none of it in the interview on Saturday morning.
Multiple times he stated he'd be "judged at the poll", maintaining nobody would take his term from him – despite the fact that the optimal path of preventing Nigel Farage and Reform UK getting to No 10 may be for Labour to replace leader.
"This is the fight of our times and I intend to guide the party," he declared.
The problem for the prime minister is that he will be scrutinised well ahead of then – in a huge set of elections in May across the UK. He attempted to contend, maybe excessively, that they are about who runs local authorities, and who runs the governments in Holyrood or Cardiff – and not about Westminster.
Accurate – up to a point. But even though he may not want to acknowledge it, No 10 will be evaluated by those elections too.
This did not stop Sir Keir implying that there were no situation under which he would resign, even if one of his MPs ran against him for the job, if those elections be catastrophic for Labour.
He attempted to account for his low poll ratings by saying the public was naturally eager for things to improve. He tried to convince me, and the nation, that the coming months would be different.
The economy would improve notwithstanding rising unemployment, he argued, when strategies the government implemented during their first rocky year began to take effect.
His central argument is that in 2026 the country will "reach a turning point".
The prime minister may have spoken with more energy than I've seen from him for a while – calmer, perhaps, with more time to talk.
However, in spite of encountering calls from many directions for a more decisive strategy, with increased political vision, more dynamism, more pace and more urgency, his explanations were well-known ones.
When he finds himself in such significant political peril, is a different approach required a change of tack?
No administration, and certainly not one that has been struggling in the polls for an extended period, has everything its as planned.
The Prime Minister's challenges are not just because governing is hard, but because he and his colleagues have made mistakes, even in the recent past.
The prime minister expressed regret that he was sorry for saying he was "delighted" to see the return of the Egyptian-British activist Alaa Abd El Fattah to the UK after an controversy when statements he'd made in the past – such as calls for Zionists and police to be killed – came to light.
Starmer attributed it to "the system" for failing to identify what the activist had said before – a more diplomatic way of saying it wasn't his responsibility.
And he is inviting obvious political risks as the year unfolds. His close relationship with the US president acquires a new complication after Trump's military action on Venezuela.
Having interviewed Sir Keir Starmer, a ex- human rights lawyer who was against the war in Iraq, over his career, the idea he would be at ease with this kind of intervention seems unlikely.
He stated he was a "career-long proponent of international law" but the public "simply do not have the complete details at the moment".
Some demanded condemn it before the interview. And the government is likely to face further scrutiny to give an explicit view in Parliament in the near future.
There has also long been bubbling desire in the Labour party to revisit some of the results of Brexit.
The PM rejects he's pursuing that, but his new more concrete plan to move closer with the European trading bloc – the huge economic European market – will probably trigger protests that he is breaking his vow never to try to overturn the choices that followed Brexit.
A move to integrate into more of the single market will delight a faction on his own side, but it is simple material for Reform and the Conservatives to