Why do you think that it would take some sort of revolution for a MP to vote against their party? It is far from uncommon for a member to abstain or vote against their party line; we saw, just yesterday, that the Cons had to concede on the issue of abortion as their party members would have voted for it and on the other side 50 Labour members went against Corbyn's orders. The reality is that it is going to be very difficult for May and her government going forward.