Andy Burnham, Mayor of Greater Manchester (Image: Getty) Andy Burnham is reportedly weighing up the option of calling a snap general election if he takes power in No.10. Allies of the Greater Manchester Mayor say the move is being actively discussed as part of early planning should he succeed in a leadership bid against Sir Keir Starmer. He is also understood to be lining up Home Secretary Shabana Mahmood to become Chancellor, according to Labour insiders. The speculation comes as Mr Burnham prepares for what could be a dramatic return to Westminster via the upcoming Makerfield by-election, where he is the narrow favourite to win next month after Labour MP Josh Simons stepped aside. Read more: Pollster finds worrying fact about Rupert Lowe that will infuriate Nigel Farage Read more: POLL: Should Ed Miliband be the next Chancellor? Andy Burnham launches Makerfield by-election campaign If successful, he would then be expected to launch a direct challenge to Sir Keir Starmer for the Labour leadership, with supporters claiming he is best placed to take on Nigel …