The Labour MEP Julie Ward

A grassroots group of Jeremy Corbyn supporters and trade unions is to launch a major UK speaking tour, billed as the leftwing campaign to remain in the EU.

The Left Against Brexit tour will attempt to persuade Corbyn and his allies of the leftwing case for a pro-EU position and will argue that the party can reap electoral benefits from a shift.

Speakers on the summer tour of British cities will include Manuel Cortes, the general secretary of the transport union TSSA, Michael Chessum, who was on Momentum’s first steering committee, the Labour MEP Julie Ward, the former shadow minister Catherine West, and the Green party co-leader Caroline Lucas.

Organisers will argue that a Corbyn-led programme of economic reform would be hampered by a damaging departure from the EU, threatening jobs and investment.

The speakers will not call for a rerun of the referendum on EU membership, but for Corbyn to formally reject leaving the EU and make the case that a vote for Labour would be a vote to remain – although the UK is set to formally exit the bloc before the next scheduled election in 2022.

“There is nothing about Brexit that will make life better for the working class,” Cortes said. “It was a rightwing brainchild won – and only narrowly – on a deceitful programme…