The Mayor of London, Sadiq Khan, has urged Labour not to block Andy Burnham's by-election candidacy during a speech at the Fabian Society meeting at Guildhall, London. Speculation has surrounded a possible return to Westminster for the mayor of Greater Manchester since Andrew Gwynne announced he would resign as an MP on health grounds on Thursday (January 23). Mr Burnham, who is widely believed to have ambitions to lead the party, is yet to comment on whether he intends to stand. If he does put