"I know there are those who doubt me and I know I have to prove them wrong and I will," Starmer said in a speech on Monday.
I know that people are frustrated with the situation in Britain, frustrated with politics and that some are unhappy with me.
Starmer also promised to restore the relationship with Europe, to place "Britain at the centre of Europe" and to nationalise the steel giant British Steel.
On Friday it became clear that his social-democratic Labour Party had performed disastrously in the local and regional elections. The far-right Reform party was the big winner.
This has increased criticism of the Labour leader. On Monday evening, the BBC counted 70 of the party's MPs who have called for him to resign.
Four secretaries to ministers in the Starmer government have resigned.
But the mood of rebellion is not total among Labour MPs. Among those supporting Starmer is Mike Tapp.
"The country needs stability, not a revolving door for new leaders," he said, according to the BBC.
