Lawmakers rejected Prime Minister Theresa May's Brexit deal for a third time on Friday, sounding its probable death knell and leaving Britain's withdrawal from the European Union in turmoil on the very day it was supposed to quit the bloc.

The decision to reject a stripped-down version of May's divorce deal has left it totally unclear how, when or even whether Britain will leave the EU, and plunges the three-year Brexit crisis to a deeper level of uncertainty.

"I fear we are reaching the limits of this process in this House," May told Parliament after the defeat. "The implications of the House's decision are grave."