Politicians and lobby groups who support penalty rates cuts have been accused of hypocrisy after the Greens “cheekily” tried, but failed, to have Parliament sit on Sunday.

As MPs eyed a marathon sitting day on Thursday, Senator Scott Ludlam hit out at the Coalition over what he labelled the “seething hypocrisy” of politicians who approved of weekend pay cuts.

He said politicians who support reducing weekend rates had claimed that “nothing [is] special about Sundays any more”, yet all their electorate offices were closed.

“That is the scale of the seething hypocrisy that we are dealing with,” Senator Ludlam told Parliament.

“It would be so interesting to take a straw poll, and it is a shame we cannot put it to a vote, as to how many on this side of the chamber would be interested in coming back here and working on a Sunday.

Greens Senator Scott Ludlum spoke in favour of having the Senate sit on Sunday. Photo: AAP

“I don’t think there would be many takers, quite frankly. That is why we pay people a premium to work on Sundays or late into the night.”

The Greens had “cheekily” proposed to have the Senate adjourn at 10.30pm on Thursday and return on Sunday, Senator Ludlam said.

But it was not voted on because of “the speed with which the Attorney-General [George Brandis] chopped through the hours motion”.

“We are probably going to sit until late into the night, and that is reasonably well understood by everybody in here,” he said.

“But here is the fascinating thing. There are a number of trade union campaigners who, in the wake of the Fair Work Commission decision, visited the premises of those who had argued the most fiercely that Sunday penalty rates should be cut, and guess what they discovered?”

“Their offices were all closed so that those people could spend time with their families and maybe go to a coffee shop, grab a cup of coffee and be served by somebody earning Sunday penalty rates.”

Watch Senator Ludlam’s speech

Parliamentarians sat until midnight on Thursday and through to an extra day on Friday as the government attempted unsuccessfully to legislate a change to section 18C of the Racial Discrimination Act, and strike a deal on its business tax cut plans.

Also on Thursday, Labor deputy leader Tanya Plibersek launched a scathing attack on a Liberal MP who noted during a penalty rates debate that he’d worked on Sundays his whole life.

Ms Plibersek was speaking about a cleaner, Margarita, who Labor and the unions brought into Parliament to pressure the government over penalty rates.

Reid MP Craig Laundy, a former hotelier, appeared to interject, according to Ms Plibersek, to say that’d he worked Sundays all his life.

“How much did you get paid for working Sundays? I tell you it wasn’t the minimum wage was it?” Ms Plibersek said.

“No, you did pretty well out of working Sundays, didn’t you?”

The Turnbull government has been under pressure over the Fair Work Commission’s decision to reduce Sunday rates for retail, fast food, hospitality and pharmacy award workers.

It has accused Labor of backflipping on the issue, pointing to previous comments by Opposition Leader Bill Shorten that he would accept the commission’s decision.