LONDON (REUTERS) - Britain's deeply divided opposition Labour Party seems to be heading for a contested leadership election with its leader Jeremy Corbyn refusing to resign, the party's deputy leader Tom Watson said on Wednesday.

Corbyn is popular with the party's membership but Labour lawmakers passed a motion of no-confidence in him this week after what they saw as his lacklustre performance in the EU referendum campaign this month, which ended with Britons voting to leave the bloc.

"It's a great tragedy," Watson told the BBC.

"He does have a members' mandate but those members who joined the political party know that you also need a parliamentary mandate if you are to form a government."

Asked whether he had told Corbyn to resign, Watson said: "I'm afraid Jeremy was not willing to discuss that with me so I'm assuming he remains in office."

"It looks like the Labour Party is heading for some form of contested election," he said, adding "I won't run."