All graduates at Scottish universities should pay a financial contribution when they finish their studies, according to a thinktank.
Reform Scotland also said students from EU countries should pay fees next year as the “survival” of the higher education sector is at risk from the coronavirus crisis.
It comes after university bosses have raised alarms about the impact of the lockdown on their finances.
Sally Mapstone, principal at St Andrews, recently warned it was facing a £25 million black hole. She has taken a 20% pay cut while hundreds of staff are furloughed.
St Andrews is preparing for remote learning in the autumn, while Dundee and Abertay universities have both said they are delaying the start of their terms.
The graduate endowment fee was abolished in 2007, meaning Scottish students do not have to pay towards the cost of undergraduate tuition.
Fees are still charged to students from the rest of the UK and outside the EU. A paper released by Reform Scotland said it is “fair” that graduates should pay back part of their tuition once they are earning the average Scottish salary.
Director Chris Deerin said: “Coronavirus has had a devastating impact on many areas of Scottish life, particularly those which were already under pressure before the pandemic hit.
“There is no better example of this than the university sector. Over half of our universities were already in deficit before coronavirus, and increasingly reliant on fee-paying students from… the rest of the world to stay afloat.
“We would all like to live in a world where ‘free’ university education works for the universities, the students and the taxpayer. But it’s time to admit that it doesn’t.”
He added: “Graduates should pay back a proportion of their tuition fee once they start earning the average Scottish salary.
“This is fair because graduates on average earn more money throughout their lives than non-graduates, and it is also reasonable because those who never earn enough money to pay back their tuition will never have to do so.”
The paper says introducing fees for EU students next year would remove a cap on the number of Scottish students who can attend universities.
Titled A Degree Of Fairness, the paper says it would be “bizarre” for the Scottish Government to continue paying EU students’ fees after Brexit.
A Scottish Government spokesman said: “We remain committed to free higher education for Scots-domiciled students and access to university being based on the ability to learn, not the ability to pay. We fully realise the detriment that losing international students from our education system will have in 2020-21 and beyond.
“We are working in partnership with universities and colleges to address the challenges and announced on May 6 an additional £75 million for research.”
He added that Scottish Ministers continue to ask the UK Government for “appropriate fiscal support” for the sector.