A vote to leave the European Union would have a devastating impact on the life chances of young people, Education Secretary Nicky Morgan has said.
Entering the debate over EU membership, she urged parents and grandparents to think how their vote would affect opportunities for the next generation.
She also told young people to make sure they voted in June's referendum.
The Vote Leave campaign said the EU had been bad for young people, with a generation on the continent unemployed.
Speaking on BBC Breakfast ahead of a speech at the Fashion Retail Academy in London, Mrs Morgan said companies were already suspending hiring decisions as they waited for the outcome of the vote on 23 June.
"As we saw from the recession that we've just been through, the people who suffer most are the youngest. Those who are trying to get into jobs and careers will suffer if companies and organisations are not hiring," she said.
In her speech, she argued there had already been a drop in advertised job vacancies because of employers' fears of a British exit - or Brexit - from Europe.
"It's clear, that if Britain leaves Europe it will be young people who suffer the most, left in limbo while we struggle to find and then negotiate an alternative model. In doing so we risk that lost generation becoming a reality," she said.
"And everyone who casts their vote must understand that. If parents and grandparents vote to leave, they'll be voting to gamble with their children and grandchildren's future.
"At a time when people are rightly concerned about inter-generational fairness, the most unfair decision that the older generation could make would be to take Britain out of Europe and damage the ability of young people to get on in life."
Mrs Morgan said young people were "the generation of Instagram, Easyjet and eBay" and rejected isolation in favour of internationalism.
"They don't want to see a Britain cut off from the world, where not only their opportunities, but our influence as a country, ends at our shores.
"These young people have grown up in a world where international co-operation, economic growth, technological advancements and social media, have seen barriers being torn down across the world.
"Young people today want to see the UK working internationally to tackle the big problems and issues that they care about because they want to make their world a better place."
Her views were backed by the National Association of College and University Entrepreneurs, an organisation which supports students in developing their entrepreneurial ideas.
Chief executive Johnny Luk said: "We have the best of both worlds. We do not need to bail out any eurozone countries, we have our own currency and have a strong say in an important members' club.
"I truly believe the UK should remain part of the European Union to ensure new businesses can flourish and help build a stable society."
Other senior Conservative figures, such as Iain Duncan Smith, have said EU membership makes it harder to control borders and reduce the number of people coming here to work, which has an impact on young people.
Vote Leave said Mrs Morgan is wrong to claim there has been a drop in job vacancies.
The campaign's spokesman, Robert Oxley, added: "It is depressing that the education secretary is so willing to do down the chances of young people as part of Number 10's desperate bid to win the referendum.
"The EU has not been good for young people, driving up costs and forcing down wages while leaving a generation unemployed on the continent."
The referendum on Britain's place in the EU will be held on Thursday 23 June.