Rob Stothard / Stringer / Getty Images New grassroots Labour movement calls on Jeremy Corbyn to back a second referendum on Brexit. Labour For A People's Vote, unveiled on Monday, wants the Labour leadership to block Theresa May's Brexit deal and support a referendum on staying in the European Union. The group is supported by 62 local Labour parties and left-wing figures like John McDonnell's advisor. Corbyn is trying to juggle the party's pro-Remain membership and Labour-held constituencies which voted Leave. LONDON — Jeremy Corbyn is coming under increasing pressure to back a second referendum after a grassroots campaign led by Labour members calling for the party to oppose Brexit was unveiled on Monday. The group, called Labour For A People's Vote, claims to have the support of 62 local Labour parties and thousands of party members across the country.