Gordon Brown will today make a direct plea to Labour supporters to vote to remain in the EU at the referendum.
In a campaign which has been dominated by Conservative infighting, the former prime minister will tell Labour voters the EU can deliver "positive, practical and progressive benefits".
And he will warn as many as half of Britain’s young people may not vote in the June 23 referendum, making Brexit more likely.
"Today I am speaking directly to the UK’s nine million plus Labour voters and the 15million voters who would not vote Conservative," he will say.
"I am speaking today directly to young people who may not yet have registered to vote, to mothers who will vote based on the future prospects for their children and to millions of people who believe that globalisation, supported by the European Union, has sadly been a one way street to job losses.
"They want answers as to how Europe can be good for them in the years to come and on that basis they will decide not just how to vote but whether to vote at all."
Brown will highlight a poll conducted by Hope Not Hate which shows, by a margin of four to one (62% to 15% with 23% known), Labour supporters aged 18-30 want to stay in the EU.
He will add: "It is feared as many as half of Britain’s young people may not vote. 30 per cent of young people – twice the national average – are not registered to vote and many students registered at their college address risk losing the right to vote as they will not be there when ballot papers get sent out. I urge all voters to register to vote by theJune 7 deadline. "
A separate survey by Universities UK yesterday found up to 200,000 students face missing out on a vote in the referendum because they do not know it is taking place in the holidays and are registered to vote in the wrong place.
Of just over 2,000 students surveyed, 63% could not name the date of the vote and 54% were not even aware it was being held in June.
That is despite most (54%) saying they had given the question some thought and another quarter "a lot of thought"- with 48% saying they would definitely vote.