The new Labour leader won 379 of 403 MP nominations unopposed and pledges to end the revolving door at No. 10 — seven since 2016.

"We must recognize that this generation of politicians, myself included, have failed to challenge a political culture and an economic model that simply doesn't work well enough…

Andy Burnham Set to Become UK Prime Minister, Vows Leadership for All

The United Kingdom's new Prime Minister Andy Burnham delivers a speech outside 10 Downing Street in London after taking office on Monday. [Isabel Infantes / REUTERS]

Andy Burnham promises unity and tangible improvements as he steps into the UK premiership amid pressing challenges and cabinet uncertainties.