Senators will apply fresh scrutiny to the government’s new workplace laws that will enshrine multi-employer bargaining as an inquiry into the overhaul gets under way.

A new round of hearings will on Friday be held into the industrial relations bill, which passed the lower house on Thursday.

However, the government will still face hurdles for the bill to pass the upper house, with both the Greens and at least one senator needed for support.

The inquiry will examine the impact the bill will have on encouraging bargaining for single enterprise agreements, improving job security, and the decision by the government to abolish the construction sector watchdog.

The inquiry is set to wrap up before the legislation is introduced to the Senate later this month.

While the government wants the laws passed by the end of the year, there are just eight sitting days left before parliament rises for the summer break.

Further changes to the laws are expected to be made when debate resumes, but Workplace Relations Minister Tony Burke is confident of the bill’s success.

“I’m realistic. I know that we have to negotiate for this,” he said.

“But I am doing everything I can to get this bill through with as many protections for workers as I possibly can.”

While the opposition has accused the government of trying to race the laws through parliament, Mr Burke said speed was needed to boost pay packets for workers.

“You can negotiate forever. And what happens during that time? We continue with wages being kept low,” he said.

Opposition workplace spokeswoman Michaelia Cash said the laws would lead to more strikes and would affect workers.

“This is a terrible bill rammed through in a disgraceful abuse of the parliament,” Senator Cash said.

“With this bill imposing such drastic changes to our IR system the very least parliament deserved was adequate time for debate.”

The debate comes as the government appointed an acting president to the wages umpire.

Adam Hatcher will be the acting president of the Fair Work Commission, following the retirement of Iain Ross.

Mr Hatcher, who has been vice-president of the commission since 2013, will have a three-month term starting from November 19.

– AAP