Labour Party Leader Jeremy Corbyn meets former military personnel | Ian Forsyth/Getty Images Unions agree Labour should back second Brexit referendum Labour could still support leaving the EU under a Brexit deal of its own.

LONDON — The Labour Party has been given the green light to throw its weight behind staying in the EU in a second referendum, after its union backers agreed a new position.

But, under the plan, Labour could still support leaving the EU under a Brexit deal of its own instead of staying in the bloc.

Union bosses agreed on Monday that the party will demand a referendum on any deal struck between the governing Conservative Party and the EU, and would back Remain.

Labour would also call a referendum if it wins power and renegotiate a fresh pact with Brussels — but could then back that deal over continued EU membership.

The strategy was revealed in a document posted on Twitter Monday evening, which party officials confirmed is accurate.

Leader Jeremy Corbyn has come under huge pressure from within his own party to fully support a second EU referendum and back staying in the bloc.

He met the leaders of 12 affiliated trade unions on Monday, including Unite, the biggest financial backer of Labour, whose boss Len McCluskey was holding out against a shift in the party’s position on Brexit.

But the document agreed by the unions said: “The Labour Party should confirm that whatever deal is negotiated by the new Tory prime minister or an exit based on no deal should be put to the people in a public confirmatory vote.”

It said such a referendum should offer the choice of the Tory position (either a deal or no deal) versus Remain, and that “in this event the Labour party should campaign to remain in the European Union.”

It said that, in the event of a general election, the Labour manifesto policy should be to renegotiate a new deal with the EU and seek a customs union with the bloc.

That deal would then be put to the public in a referendum, with the options of choosing the exit package or staying in the EU.

But the document added: “The Labour Party's campaign position on such a ballot should depend on the deal negotiated.”