Who is Andy Burnham? And 4 other things investors should know as the U.K. replaces its prime minister

LONDON, ENGLAND - JUNE 22: Andy Burnham, Labour MP for Makerfield, takes a "Selfie" with the Parliamentary Labour Party after his swearing-in at the Houses of Parliament on June 22, 2026 in London, England. Last week Andy Burnham won 54% of the vote in the Makerfield by-election, paving his way to return to Westminster as an MP and challenger to Prime Minister Keir Starmer's leadership. (Photo by Dan Kitwood/Getty Images) Dan Kitwood | Getty Images News | Getty Images U.K. Prime Minister Keir Starmer announced Monday he'd step down , opening the door for Britain's seventh leader in 10 years. The process to succeed him as Labour Party leader and prime minister will see a successor take the helm by September 1 at the latest, and with a new administration comes a new set of economic and fiscal policies for markets to digest. Here is what investors should know while the U.K. searches for its next leader. First up, the frontrunner. Who is Andy Burnham? Andy Burnham is the favorite to succeed Starmer. The mayor of Greater Manchester won a seat in Britain's parliament in a special election last week, making him eligible for the leadership. On Monday morning, former health secretary Wes Streeting, who had been a potential rival for the premiership, endorsed Burnham, boosting the chances that he will run unopposed, which would significantly shorten the process. …