Gordon Brown and John McDonnell will join forces in a bid to convince Labour voters to back a Remain vote, with just one week to go before the 23 June referendum. The former prime minister and current shadow chancellor will warn against a "Tory Brexit", as they address a Labour In for Britain rally in Manchester on 16 June.
"In the 1980s the Tories turned our industrial heartlands into industrial wastelands," Brown will say. "Their ideology was that there was no such thing as society and everyone was on their own.
"What stood between our communities and further devastation was the European structural funds, regional funds and social funds that Tory Brexiteers would now cut. European money is necessary for renovation, renewal and regeneration – and right across the North, Scotland and Wales it is still vitally needed now."
He will add: "All my political life I have fought for jobs and a vision of full employment for our country. To achieve this, we need to send our exports to where we sell most – the EU. I estimate that 500,000 more jobs can be created in Britain in the next ten years from reform of the single market, the European infrastructure program and co-operation in the energy and environmental industries."
Meanwhile, McDonnell will claim that British households could be better off to equivalent of £1,300 by avoiding a Brexit. "Under Labour's plans we could secure an additional £35bn in additional funding, which would mean households would better off to the equivalent of £1,320," the left-winger is expected to say.
"This injection of Labour Investment could be a boost to British families struggling to get to the end of each month. That is why we want Labour voters to vote next Thursday for Labour Investment in a reformed EU, and reject a Tory Brexit."
The comments come as Labour to the lead in Remain campaign, amid fears that the party's voters could be put off by a pro-EU vote by Conservative leader and Prime Minister David Cameron. Immigration has also become a top issue in referendum, with Vote Leave backing an Australian-style points system after official figures showed net migration to the UK climbed to 333,000 in 2015.
German-born Labour MP Gisela Stuart, the chair of Vote Leave, claimed her party's supporters have seen "through the spin of the government". The Eurosceptic also added: 'We had an opportunity to get positive changes out of the EU but David Cameron blew it with his failed renegotiation.
"Labour voters have seen through the spin of the Government which is why they are rejecting the IN campaign and no amount of hastily cobbled together relaunches will change that.
"As my own experience with the EU constitution taught me, Brussels only heads in one direction seizing more power and money from member states at every opportunity. If we want to take back control of our borders, economy and democracy, if we want to stop handing Brussels £350m a week and if want to create a fairer Britain, we have to Vote Leave on 23 June."