Lord Hattersley, who was a minister in the Wilson and Callaghan governments, will declare his support for the People’s Vote campaign in a speech in Sheffield on Saturday.
The former deputy Labour Party leader is expected to tell Jeremy Corbyn to “put out of his mind all the outdated nonsense about a socialist economy being impossible in Europe”.
Speaking alongside Labour former cabinet minister Dame Margaret Beckett and Liberal Democrat leader Sir Vince Cable, Lord Hattersley will say there is “no conceivable deal which is remotely as beneficial to Great Britain as full membership of the European Union”.
The 86-year-old has previously said leaving the European Union will be a “disaster”.
Lord Hattersley will say: “Jeremy Corbyn promised the party, that policy would be made by the membership. Conference resolutions would he said, be implemented.
“That means he must, difficult as it may be, put out of his mind all the outdated nonsense about a socialist economy being impossible in Europe.
“The vast majority of party members now expect that when the hope of an early general election is extinguished, Labour will campaign for a People’s Vote.”
And he will warn that young people in the UK will “pay the price” from Brexit, while the elderly would be “protected” from the long-term “penalties”.
“There is no conceivable deal which is remotely as beneficial to Great Britain as full membership of the European Union.
“None of us – and that includes the leadership of the Labour Party – ought to waste our time talking about another renegotiation.
“Support for a People’s Vote on Britain’s future grows stronger every day. If it were backed by the Labour Party, and in consequence, by the progressive trade unions, the idea would be irresistible.
“The People’s Vote must enfranchise the young – not because they are passionately in favour of a European future, but because the Europe we build this year will belong to them.
“The elderly – people like me – would be protected from the long-term penalties of leaving the Union or hovering half in half out.
“We can rely for a year or two on the prosperity which is bequeathed to us by 40 years of European membership. It is the young who will pay the price if Little England rises from the dead – reduced job opportunities, a retarded rate of economic growth and investment diverted from Britain to tariff free markets.”
Tory former minister Anna Soubry and Labour MP for Wakefield Mary Creagh will also speak at the event as part of the People’s Vote campaign’s national “Day of Action”.