Left-wing candidate Andrea Egan has been elected as the new leader of Unison, the UK's biggest trade union, in a blow to Sir Keir Starmer.

Ms Egan, who was expelled from the Labour Party three years ago, beat the union's current general secretary Christina McAnea, an ally of the prime minister.

Following her election, Ms Egan promised to "stand up to any employer, politician or cabinet minister who acts against our interests".

During her campaign, she had pledged to hold Labour's "feet to the fire" and refuse to write the party "blank cheques".