Andy Burnham, the former Mayor of Greater Manchester and the new Prime Minister of the United Kingdom, has picked a challenging time to enter office

Andy Burnham begins his first full day as U.K. prime minister on Tuesday, after entering 10 Downing Street on a wave of enthusiasm and a mountain of challenges ahead.

The U.K.'s Andy Burnham enters 10 Downing Street on Monday with enthusiasm behind him, but major challenges ahead

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]