Students should “live very modestly and have a frugal existence” if they run out of cash, the universities minister has suggested.

Jo Johnson dismissed criticism that students are struggling with rising living costs, claiming those “focusing on their studies” managed to get by.

The comments, made at the Conservative party conference, threatened to torpedo the party’s attempts to win back support from young people who have deserted it.

The higher education minister came under fire from consumer finance expert Martin Lewis, who said means-testing reduces many students’ maintenance loan to just £5,000 a year.

Their “biggest problem” was not tuition fees but the fact that the “loans aren't big enough” to cover the costs of being at university, Mr Lewis said.

And Labour MP Wes Streeting a former president of the National Union of Students, said: “Ministers need to get real about the real pressures on students' finances.

“Too many students are now struggling to make ends meet on student loans alone and, even where they can find part-time work, students from the poorest backgrounds have less time to spend on their course because they're spending too much time stacking shelves or pulling pints.

"Instead of tinkering around the edges with tuition fees, the Tories should re-introduce non-repayable grants for the poorest students, which they so callously scrapped.”

The Manchester conference opened with a pledge to freeze tuition fees at £9,250 and cut post-graduation costs by hiking the threshold for repayments from £21,000 to £25,000.

Theresa May has also promised a “review”, a recognition that Jeremy Corbyn’s promise to abolish fees altogether has transformed the terms of the debate.

But, speaking at a fringe meeting, Mr Johnson insisted students had other options to cover their expenses, including keeping their spending as low as possible.

"There may be a gap but that doesn't necessarily mean it's a gap that must be filled by parental contribution. There are many other ways in which students could fill that gap,” he said.

"They could work as many, many students do, they can also save. Then, of course they can borrow from their parents if they wish, but it isn't necessarily a parental contribution.

“What is also so important to bear in mind is that students have many different choices about the kind of lifestyle they want at university.

“Some students want to live very modestly and have a frugal existence, focusing on their studies. Other students may want a different lifestyle but there isn't one cost of going to university, it's a very specific choice that each student must make.”

Earlier, the Government was warned that its U-turn on repayments was a “big and expensive giveaway” that will raise the cost of higher education to the taxpayer by 40 per cent.