As Keir Starmer is set to announce his premature resignation as UK prime minister, Andy Burnham is the frontrunner for succession to the coveted post. Britain's Labour party's Andy Burnham with his wife Marie-France Van Heel and their daughter Rosie. (AP Photo)Burnham is currently the mayor of Greater Manchester and is seen as Keir Starmer’s biggest rival in the Labour Party.This is partly due to the 56-year-old being perceived as politically left-leaning, which has been a traditional Labour stance before Starmer came along and tried to position himself as centre-right to counter Reform UK’s growing popularity, a strategy that seems to have backfired spectacularly.Burnham is considered as Starmer's biggest would-be rival. One of the reasons could be that he's perceived to be to the political left of the prime minister. He has earned the moniker “King of the North”, with reference to the popular Jon Snow character in “Game of Thrones”, given his fierce backing of northern England.He marked big wins in three mayoral polls since 2017.