LONDON: A group of lawmakers from Britain’s opposition Labour Party said on Wednesday they had formed an organization to campaign to quit the European Union should Prime Minister David Cameron’s plan to renegotiate Britain’s ties with the bloc fail.

Cameron has pledged to reshape the country’s EU ties before holding an in-out EU membership referendum by the end of 2017 and the move highlighted the existence of long-standing divisions in the center-left Labour Party over Europe.

The creation of the group, Labour for Britain, also raised the prospect of Labour members of parliament joining forces with Euroskeptics from Cameron’s right-leaning Conservatives, who are also split on the issue.

Labour, which suffered a crushing defeat to Cameron’s party in a national election only last month, recently dropped its opposition to his pledge to hold a referendum though its official position remains staying in the EU.

But a group of Euroskeptic Labour lawmakers and the party’s largest private donor said on Wednesday that unconditionally uniting behind the ‘in’ campaign would “significantly weaken” Britain’s negotiating position.