As the government looks to pass legislation before the end of the year, Workplace Relations Minister Tony Burke said new amendments would be introduced on Tuesday.

The bill includes multi-employer bargaining and the ability to force businesses to cater for requests for more flexible work hours.

Under the amendments, a majority of support will be needed of employees from each employer for a single-interest bargaining authorisation

Businesses and workers also won’t be compelled into a single-interest employer agreements when they have agreed to bargain for a single-enterprise agreement.

Further changes will also be made to the better off overall test to make sure new employees under an agreement won’t be left worse off.

The Fair Work Commission will be required to be satisfied a minimum period of good-faith bargaining has occurred before moving to arbitrate.

And businesses will be given one year to adjust to changes to fixed-term contracts.

Announcing the amendments on Monday, Burke said they were “sensible improvements” to the bill.

“Single enterprise agreements will remain the primary form of agreement and this bill makes important improvements to get more people on to single enterprise agreements,” he said.

“We’re also opening up the multi-employer pathway for people who haven’t been able to access single enterprise agreements, particularly low-paid workers in female-dominated industries.”

Earlier key senator crossbenchers Jacqui Lambie and David Pocock queried some of the elements of the government’s plan.

Senator Lambie says she’s waiting for a guarantee the changes will push up wages, which is the government’s main justification for the bill despite opposition from business.

“Because the only one that seems to be selling that point is (Workplace Relations Minister) Tony Burke and the unions,” she said.

The independent Tasmanian senator said keeping the building and construction watchdog – which the government has committed to abolishing – was also a sticking point.

“Somebody needs to be policing (the industry). I thought it was working quite well, to be honest with you,” she said.

Pocock has proposed splitting the bill and solely voting on the non-controversial aspects, such as measures to improve gender pay equity, before Christmas.

The government needs the vote of at least one crossbencher on top of the Greens for the legislation to pass the Senate.

“This is not about delaying,” Pocock wrote on Twitter.

“By splitting the bill we can pass the parts of it that are straightforward and supported across the board and take the proper time to understand and refine parts that aren’t.”

Australian Council of Trade Unions president Michele O’Neil said workers couldn’t wait any longer for a pay rise, with wages stagnant for a decade and real wages going backwards for more than year.

O’Neil also said business groups were trying to stop wages from rising by opposing the multi-employer bargain components of the bill.

Nationals leader David Littleproud agreed the bill needed more time to be scrutinised.

“This won’t increase wages by Christmas,” he said.

Greens leader Adam Bandt said his party would need to see what changes the government makes to the bill before declaring support for it.

“We need industrial relations that work for women … that work for carers … and lift wages for the lowest paid,” he said.

-AAP