In an Observer interview, the prime minister said he would lead Labour into the next election due by mid-August 2029 and serve a full second term.
His pledge comes as pressure grows inside the governing Labour Party for him to quit and rivals threaten a leadership challenge within days.
The remarks seek to project stability amid mounting internal unrest, with Starmer publicly rejecting speculation that he could be forced out before the next vote.
As rivals circle and his authority crumbles, what is Keir Starmer's last-ditch strategy to avoid being ousted before the 2029 election?
Could Nigel Farage's surging Reform UK party capitalize on Labour's collapse to win the next general election?
With voters deserting Labour for both the Greens and Reform UK, is Britain's traditional two-party system now permanently broken?