The federal government is tweaking the rules around temporary foreign workers while it works on an overhaul to the controversial immigration program.

The government has scrapped the cumulative-duration rule — also known as the "four-in, four-out" rule — which limited how long temporary foreign workers could stay in Canada.

After four years, the worker would have to leave Canada for four years or stay as a student or visitor. The government said the change will "prevent unnecessary hardship and instability for both workers and employers."

The first round of workers was approved under this rule in April 2011. Their work permits expired in April 2015, with no chance of renewal.

The government will also require some employers to advertise low-wage work to Canadians first, specifically targeting groups that are "under-represented" in the labour force — youth, persons with disabilities, Indigenous people and newcomers. Employers will be required to advertise to between two and four of those groups "where appropriate."

Those changes have not yet come into effect.

Path to permanent residency

The government is keeping a cap that was phased in under the Conservatives on the proportion of temporary foreign workers that can be employed at a worksite.

The cap is 20 per cent for employers who were approved under the program before June 20, 2014 and 10 per cent for those approved afterward. Seasonal industries are exempt from the cap for up to 180 days of next year.

The government said it is "further developing pathways" to permanent residency for temporary foreign workers as part of its comprehensive review.