Post-study work visas would be brought back under the Liberal Democrats, Tim Farron has revealed.
Graduates in science, engineering and maths who found suitable employment within six months of finishing their studies would be eligible.
Party leader Mr Farron announced the Liberal Democrats' plan for a more nuanced version of the visa on Monday.
He criticised the decision of then home secretary Theresa May to scrap the visas entirely in 2012, saying they shouldn't have been done away with completely.
Speaking during the party's first official day of campaigning in Scotland, Mr Farron said the move would be published the party's manifesto.
"It is ludicrous that we take in international students, train them, and then as soon as they are skilled and ready to work, the Conservatives boot them out of the country," he said.
"British universities are world leaders that attract some of the most talented individuals from around the globe to the benefit of the UK economy.
"But instead of encouraging them to stay here and contributing to keeping Britain at the forefront of cutting-edge research, this Conservative Brexit Government forces them out."
Mr Farron claimed that scrapping the system five years ago had been part of a "vain attempt" to reach an "unachievable immigration target".
"The Liberal Democrats want to build a Britain that is open, tolerant and united," he continued.
"This means bringing in and fostering talent, helping to boost our economy and keep Britain an attractive destination to study."
Also on Monday, Prime Minister Mrs May announced a Tory target of cutting immigration to the "tens of thousands".
But Mr Farron accused Mrs May of setting "arbitrary" limits on immigration.
"We need immigration rules that benefit the country, not the Conservative Party", he said.