Sir Keir Starmer is facing mounting pressure from Labour backbenchers to resign or set a timetable for his departure, despite his insistence he will not quit following a set of bruising local election results. The discussion around his political future has drawn comparisons with Labour predecessor Sir Tony Blair’s exit from No 10. Crucially, however, there is no obvious successor to Sir Keir, unlike Gordon Brown’s clear path at the time. Speculation is rife regarding the ambitions of his former deputy, Angela Rayner , and Greater Manchester Mayor Andy Burnham . Yet, Ms Rayner awaits the outcome of a review into her tax affairs, and Mr Burnham is not currently an MP. Former minister Catherine West set the deadline as she warned she was putting the cabinet “on notice” to “reorganise themselves”.…