The next Conservative leader, and probably the next PM has to be a committed Brexiter or the party will self distruct.
The timing of Boris' pronouncement, just days before the Conservative Party Conference, is no coincidence. The long knives are out for May, and she may not survive. If she does end up chopped into little pieces in George Osborne's freezer, then the Bumbling B is ready to take over (god help us).