Andy Burnham has hit back after a group of 20 Tory MPs begged him to back down in his fight with the government over Tier 3 restrictions.MPs from areas such as Norfolk, Lincolnshire, Herefordshire and Cambridgeshire sent the Mayor a letter saying they are 'deeply worried' about the prospect of another national lockdown.They therefore urged the Mayor to 'engage with the government's regional approach' which would offer some 'protection' to constituencies such as theirs where coronavirus rates are