Workers across Australia can now refuse to monitor, read or respond to work communication outside paid hours – unless doing so is unreasonable – after the federal government’s workplace reforms come into force on Monday.

The changes, which include a “right to disconnect”, are expected to drastically reduce the number of unpaid hours Australians work.

Workplace relations minister Murray Watt said the right to disconnect ensured the law kept pace with technology.

“What’s not acceptable is for people to be taking constant calls or constant emails with an expectation that they’re going to be monitoring and responding, when they’re not getting paid to do it,” he told reporters in Queensland on Sunday.

In the lead up to the law changes, some Australian workers have described roles that have ballooned in hours.

“I’m not a CEO, I just feel like I have a high-powered job,” part-time airline customer service worker Lizzy Grant said.

“But really I’m just a bloody customer service officer for an airline – underpaid and overworked,” Grant said, describing how a 20-hour week role would often balloon to a 40-hour workload.

The Australian Council of Trade Unions president, Michele O’Neil, says the laws were a huge win for workers during a cost-of-living crisis.

“More money in your pocket, more time with your loved ones and more freedom to live your life,” she said.

The government’s reforms also improve rights for gig workers and provisions for casual employees to transition into permanent employment.

But the Business Council of Australia chief executive, Bran Black, said it puts Australia’s competitiveness at risk.

“At a time when productivity has flatlined and insolvencies are increasing, we can’t risk making it harder to do business with added red tape,” he said.