LONDON/BRUSSELS—Opposition parties said they would try to pass a law that would force Prime Minister Boris Johnson to seek a delay to Britain’s departure from the European Union and prevent a potentially chaotic no-deal exit at the end of October.
The United Kingdom is heading toward a constitutional crisis at home and a showdown with the EU as Johnson has pledged to leave the bloc in 66 days without a deal unless Brussels agrees to renegotiate the Brexit divorce.
