The British Prime Minister has given what could be the most consequential speech of his career in the face of a possible leadership challenge.

Sir Keir Starmer has vowed not to "walk away" in the wake of devastating local election results at the weekend.

In the latest development, four ministerial aides have stepped down and ​more than 60 Labour MPs are now publicly calling for Sir Keir's resignation.

The calls have been lead by Catherine West, an Australian-born backbencher who has since backed down from her threat of triggering a leadership contest herself, but has again called on the Prime Minister to leave office by September.

• GUEST: Aleta Adoo, political correspondent for the Guardian 
• PRODUCER: Pip Cook