To prevent civil war a couple of things need to occur.
Firstly, Theresa May now can be struck off as leader of the party on communist grounds.
The market was set, decisions where made including a referendum to leave. Voting on ruling out a no-deal is voting for intervention. She has ignored the will of the people and must be ostracised.
The second requirement is the verdict from the people whether by referendum or election of what to do with those who voted against a no deal, contrary to the options beforehand, including referendum options, determined by the will of the people.
Arguably, one question put towards the people could be should the Labor party and others against the no-deal be tried for treason for clearly ignoring the will of the people and making decisions for them they had no right to undertake!!!
