Would market shock force parliament's hand on Brexit?

LONDON (Reuters) - There's nothing like a market crash to focus the minds of politicians, and Prime Minister Theresa May could find that only a plunge in British asset prices can persuade a divided parliament to back her Brexit deal. But how much do investors reckon sterling and stocks would have to tank before lawmakers decide that a "no deal" exit from the European Union must be averted?Expectations that parliament will reject the withdrawal agreement May has negotiated with the EU have..