University of Canberra politics, international relations and law student Jessica O'Neill, who supports herself with a casual hospitality job, said the cut could force her to pick up an extra shift that could prevent her from finishing course work.

Ms O'Neill, in her honours year at university, said she barely made enough to pay her expenses without the penalty rate cut.

"It pays my rent, it pays my bills, it pays for my electricity," she said.

"I'm already struggling as it is to have a work-study balance."

She makes $550 a week, including $250 on a Sunday, but the penalty rate cut might force her to seek an extra weekday shift to make ends meet.

"I guess I'll just have to see how it affects me."

Chris Ottey, 23, is a retail employee at EB Games and said it would be a loss for people with other weekday commitments, like study, who use weekend rates to stay afloat.

"You work casual because you have a lot of other things in your life," Mr Ottey said. "You're trying to move on, to get your life going."

Tegan Gough-Donnelly, 28, is a manager at clothing chain Factorie and said lower penalty rates meant she'd struggle to give employees the hours they need.

"The majority of them are in school or uni. They rely on those days to pay rent," Ms Gough-Donnelly said.

Coffee Club owner Vanessa Ji, 34, said the cuts were great news as it would help keep her small business.

"It's been too much," Ms Ji, said. "The wage has to be the same."

One of her baristas, Lara Selems, 20, felt differently and admitted it would create disincentives for her and others to work Saturday or Sunday.

"Lots of people give up their weekends," Ms Selems said. "You want to spend time with your family and friends."

Canberra Business Chamber chief executive Robyn Hendry said the decision was important for Canberra.

"We need to diversify our economy, we can't rely as we once did on federal government expenditure," Ms Hendry said.

"We need to play to our strengths and some of our strengths are in the tourism sector and certainly we've seen an enormous boost in the hospitality sector."

Ms Hendry argued cuts would create jobs to tackle youth unemployment and said the Fair Work Commission recognised the culture around the value of Sundays had changed.

Unions ACT secretary Alex White said when the Grand Final played on Tuesdays and parliament sat on Sundays, Australia would know the culture around weekends had changed.

Mr White said ABS data indicated 70 per cent of Australians still worked Monday to Friday.

He said there was no support for penalty rate cuts in the Canberra community, pointing to local polling by Unions ACT which showed eight in 10 Canberrans support current penalty rates.

"For Canberra it will affect retail, fast food, hospitality workers who will face up to a $6000 pay cut," Mr White said.

The changes to penalty rates would not effect employees under an existing enterprise bargaining agreement.

- with Doug Dingwall