LONDON (REUTERS) - Britain's opposition leader Jeremy Corbyn will face a leadership contest unless he considers his position, Labour Party lawmaker Angela Eagle said on Monday (July 4), saying she has the necessary support to trigger a challenge and is ready to do so.

Corbyn has refused to resign following Britain's vote to leave the European Union, despite an overwhelming majority of lawmakers in his own party passing a motion of no confidence in his leadership and resigning from his policy team en masse.

"I have the support to run and resolve this impasse and I will do so if Jeremy doesn't take action soon," said Eagle, who stood down as the party's spokeswoman on business issues after the EU vote and is the leading contender to launch a challenge.

"It's a week since Jeremy lost that vote of no confidence, and there are many other people up and down the country wanting him to consider his position."

Socialist Corbyn says he retains the support of the party's grassroots members who would elect the leader in any contest, and that resigning would be a betrayal of the huge groundswell of support that saw him elected to the job last September.

The outcome of the tussle for control of the Labour Party - between Corbyn's left-wing supporters and more centrist elements - will define the party's voice in the negotiations that will shape future ties between Britain and the EU.

To trigger a leadership election, a rival candidate needs the support of 51 or more elected lawmakers. Corbyn has said he will stand again in any contest to replace him.