Allowing international students to work more than 20 hours a week could distract from their studies and undermine the objective of temporary foreign worker programs, public servants warned the federal government in 2022.

The caution came in documents prepared for former immigration minister Sean Fraser as Ottawa looked at waiving the restriction on the number of hours international students could work off-campus — a policy the Liberals eventually implemented.

The Canadian Press obtained the internal documents with an access-to-information request.

Waiving the cap could help alleviate labour shortages, a memorandum for the minister conceded, but it could also have other unintended consequences.

"While a temporary increase in the number of hours international students can work off-campus could help address these shortages, this could detract from the primary study goal of international students to a greater emphasis on work, circumvent the temporary foreign worker programs and give rise to further program integrity concerns with the international student program," the memo said.

Canada's bloated international student program has been heavily scrutinized in recent months as part of a larger critique of Liberal immigration policies that have fuelled rapid population growth and contributed to the country's housing crunch.

That scrutiny led the federal government to introduce a cap on study permits over the next two years as it tries to get a handle on the program.

More than 900,000 foreign students had visas to study in Canada last year, which is more than three times the number 10 years ago.

Critics have questioned the dramatic spike in international student enrolments at shady post-secondary institutions and have flagged concerns about the program being a backdoor to permanent residency.

The memo said removing the limit for off-campus work would be in "stark contrast" to the temporary foreign worker programs, which requires employers to prove that they need a migrant worker and that no Canadian or permanent resident is available to do the job.

Fraser ultimately announced in October 2022 that the federal government would waive the restriction until the end of 2023 to ease labour shortages across the country.

The waiver only applied to students currently in the country or those who had already applied, in order to not incentivize foreign nationals to obtain a study permit only to work in Canada.

In December, Immigration Minister Marc Miller extended the policy until April 30, 2024, and floated the idea of setting the cap at 30 hours a week thereafter.

In an interview with The Canadian Press on Monday, Miller said he extended the waiver because he didn't want to interfere with students' work arrangements in the middle of an academic year.

"What I really didn't want to do is impact students in a current year that have made their financial calculations about how they will sustain themselves and how they will be able to pay for the tuition and rent and food," Miller said.

Miller said internal work by the department shows more than 80 per cent of international students are currently working more than 20 hours a week.

Waiving the number of hours international students could work was the right call given the labour shortages Canada was facing, but the policy was never meant to be permanent, he said.

Job vacancies soared to more than a million in the second quarter of 2022, but have steadily decreased since then as the economy slows.

Miller said he's now considering making a permanent change to the cap that would set it somewhere between 20 and 40 hours a week.

"It's not credible that someone can work 40 hours and do a proper program," Miller said.

He said the goal is to come up with a cap that gives students the ability to get good work experience and help them pay the bills, all while not undermining their studies.

"So what does a reasonable number of hours look like for someone here studying, knowing that they are paying three to four times, sometimes five times the price of a domestic student?" Miller said.

"I think that's above 20 hours."