Workers will gain new rights to switch off outside paid hours as part of a slate of industrial relations reforms poised to pass parliament.

The right to disconnect has won the support of the government, Greens and key crossbenchers, alongside measures giving greater protections to gig economy workers and more rights to casuals seeking permanent employment.

Unreasonable contact from employers outside paid hours will be curbed under the laws, with workers able to tap the Fair Work Commission if they’re hassled, which could ultimately result in a fine.

But there are carve-outs for bosses calling employees about changes to their rostered shifts and protections against frivolous and vexatious claims.

Unions will also be able to enter workplaces without notice to investigate underpayments if the legislation passes.

Labor’s suite of industrial relations reforms will pass the Senate on Thursday before being rubber-stamped in the government-controlled lower house.

The laws heralded the end of people forced to stay in casual employment by providing a pathway to permanent work and introduced world-leading minimum standards for gig workers, Employment Minister Tony Burke said.

“We’re poised to close more of the workplace loopholes that have been undermining wages and worker safety,” he said.

Independent senators David Pocock and Lidia Thorpe are supporting the tranche of reforms alongside the Greens after securing amendments, giving the government the numbers it needs to pass the Senate.

But the opposition has slammed the changes, saying they’ll stifle flexibility and put undue burdens and costs onto small businesses.

“None of the measures are designed to improve productivity, jobs, growth and investment which are the ingredients of a successful economy,” shadow attorney-general Michaelia Cash said.

The Australian public waited to see the full details about how the right to disconnect would operate, she said.

“Workers already have legal protections against unreasonable working hours,” Cash said.

Business groups have also hit out at the changes to industrial relations laws, saying workers already had protections against unreasonable contact from employers.

“We don’t want to see the Fair Work Commission called in to deal with the day-to-day activity of running a business, and issues should be resolved in the workplace,” Business Council chief executive Bran Black said.

“We remain opposed to the bill as a whole because it adds complexity, costs and red tape at the worst possible time, making it harder to do business.”

-AAP