Andy BurnhamAndy Burnham's decisive victory in the Makerfield by-election has done more than return him to Parliament after nearly a decade away; it has positioned the Greater Manchester Mayor as the strongest challenger yet to Prime Minister Keir Starmer's leadership of the Labour Party.The 56-year-old Labour veteran won the seat with nearly 55 per cent of the vote, clearing a crucial hurdle in his bid to mount a leadership challenge.Under Labour rules, only sitting MPs can contest the party leadership, making Burnham's return to Westminster a crucial moment in Britain's political landscape.Starmer congratulated Burnham on the victory, but the result is expected to deepen questions over his future.Congratulating Burnham on X, Starmer wrote. “Voters chose Labour’s campaign of hope and optimism over division and hate.”Who is Andy Burnham?Born in Liverpool in 1970 and raised in nearby Culcheth, Burnham joined the Labour Party at the age of 15 before studying at the University of Cambridge.The son of a telephone engineer and a doctor's receptionist, he rose through Labour ranks during the New Labour years under former prime ministers Tony Blair and Gordon Brown.First elected to Parliament in 2001 as MP for Leigh, Burnham went on to hold several senior cabinet posts, including Culture Secretary, Chief Secretary to the Treasury and Health Secretary. He also served in Labour's shadow cabinet after the party lost power in 2010.Why is he called the ‘King of the North’?Burnham earned the nickname "King of the North" during the Covid-19 pandemic when he emerged as one of the most vocal critics of Boris Johnson's government over funding for northern England.His public campaign for greater financial support during lockdowns turned him into a symbol of regional resistance and won him widespread popularity across northern England.The nickname has stuck ever since, reflecting both his influence in the region and his image as a champion of communities outside London.As Mayor of Greater Manchester since 2017, Burnham has overseen major transport reforms, including the rollout of the Bee Network, a London-style integrated public transport system. Supporters credit him with helping drive Manchester's economic growth and regeneration.A two-time Labour leadership contenderBurnham is no stranger to Labour leadership battles.He first ran for the party leadership in 2010 following Gordon Brown's resignation, finishing fourth. Five years later he mounted another campaign and was considered an early favourite before losing to Jeremy Corbyn.Despite those defeats, Burnham remained one of Labour's most recognisable figures and gradually built a political base outside Westminster through his mayoral role.Why does he pose a challenge to Starmer?Burnham's appeal extends beyond Labour's traditional support base. Many party members see him as a stronger communicator and a more relatable political figure than Starmer at a time when Labour's popularity has slumped.His supporters argue that his success in Greater Manchester and his ability to connect with working-class voters make him well placed to counter the growing threat posed by Nigel Farage's Reform UK.Critics, however, argue that Burnham has adapted his politics to suit different eras of Labour, having served under Blair, Brown and Corbyn. They also question whether his success in Manchester can be replicated on a national stage.What happens next?Burnham is expected to be sworn in as MP for Makerfield within days. That will make him eligible to contest the Labour leadership if he secures backing from enough Labour MPs.With Starmer facing mounting pressure after a string of political setbacks, Burnham's return to Westminster has intensified speculation that Britain could soon witness a leadership battle at the heart of the governing party.For now, the man once dubbed the "King of the North" has taken his biggest step yet towards a job at 10 Downing Street.