Jeremy Corbyn will on Saturday make a direct plea to young people to "step up" and register to vote to stop the Conservatives "holding them back".
The Labour leader will urge potential young voters - who could hold the key to his electoral prospects as they are more likely to back him - to overcome "apathy and resignation" because it only favours the Tories.
He will highlight figures showing 2.4 million young people missing from the electoral register and a turnout rate of just 40% among 18 to 24 year olds, who he will tell to "claim your future".
At an east London speech which is anticipated to include his most personal intervention of the campaign so far, Mr Corbyn is expected to say: "The Conservatives are more than happy with this state of affairs. Apathy and resignation will secure them seats on election day.
"It's not that our young people don't have the energy and talent to succeed. Our country is full of potential.
"But something hangs on people's lips - though it typically goes unspoken. It's the unheard story of why so many of us are scaling back our hopes and dreams in favour of just getting by.
"It's the reason why this country is unable to unleash its potential.
"Because as families, communities - entire regions - we are all being held back.
"Don't let the Conservatives hold you back.
"Don't let the Conservatives hold Britain back.
"Quite simply, only the Labour Party can deliver a Britain for the many, not the few."
Mr Corbyn will also accuse the Conservatives of preparing to deliver a "Brexit for the few" which will only benefit the super-rich and big corporations.
He will say the Tories' "friends and backers" have a "get out of jail free card" and will benefit from Theresa May's plans to hand tax cuts to the rich while at the same time she erodes workers' rights and environmental protections enshrined in EU law.
"This General Election, more than any I have previously fought, will define our times," he is expected to say.
"Make no mistake, a Brexit for the few is now brewing.
"One where any money saved is handed out as tax cuts to the super-rich and their corporations.
"Where new trade deals with the US and elsewhere are used to drive down our working conditions, and environmental and food standards.
"Do you think personal prospects of the Conservatives' friends and backers will suffer following the kind of Brexit they want to see? Do you think their lives will get harder as wages slide and jobs become even less secure?
"Unlikely, I think you'll agree. And that's because the Conservatives' backers can afford to opt out when things go wrong. They've been doing it for decades.
"In truth, they always have a get out of jail free card while this Government is at the controls."
Conservative Party chairman Sir Patrick McLoughlin said: "At this election there is a very clear choice on the ballot paper. Do you want Theresa May to protect Britain's interests through Brexit and beyond - or the weak, floundering and nonsensical Jeremy Corbyn who doesn't even have the confidence of three quarters of his own MPs?
"Only Theresa May can offer the strong and stable leadership our country needs with 27 EU countries lining up to oppose us.
"Jeremy Corbyn - propped up by Lib Dems and SNP - would bring grave uncertainty and risk to our growing economy. Ordinary working people will be the ones who pay the price with higher taxes, more debt and fewer jobs.
"There is only one way of being sure of getting the strong and stable leadership we need at this serious moment for our country - and that's by voting for Theresa May and her local Conservative candidates on June 8."