Two events in 24 hours could shape the Brexit policy of the U.K.'s main opposition Labour Party and change the course of Britain's departure from the European Union.

The decision of seven members of Parliament to quit the party on Monday and set up an independent caucus will in itself do little to alter the calculus in the House of Commons — they ignored the party line on Brexit anyway — but it could lead Labour Leader Jeremy Corbyn to review his strategy.

And if that happens, Prime Minister Theresa May could find herself fighting a strengthened campaign for a delay to the U.K.'s departure or a second referendum, which could embolden anti-Brexit rebels in her own party.