Tensions have erupted in federal parliament over workplace protections for first responders and domestic violence survivors.
Independent senators Jacqui Lambie and David Pocock pulled off a rare parliamentary tactic as they tried to force the changes through before Christmas.
The pair plucked four elements from Labor's proposed industrial laws, which cleared the upper house against the government's wishes.
Labor has fought against splitting the bill, which also contains changes to gig economy work and labour hire rules.
An emotional Senator Lambie chastised Employment Minister Tony Burke for not passing the four reforms in the lower house.
One amendment would give emergency workers easier access to compensation for post-traumatic stress, while another would protect domestic and family violence victims from discrimination at work.
"We want these protections in place by Christmas and there was not one damn reason why they shouldn't be," Senator Lambie told parliament on Tuesday.
She said the government was using the four measures to hold the cross bench hostage over its broader legislation, which the opposition and business groups did not support.
"We're about to come into a fire season, we're going to be heavily relying on first responders," Senator Lambie said.
"You don't want to give them some relief before Christmas time so they can stop fighting a bureaucratic system that ... not only destroys you as a person, but destroy your family and those around you.
"This is beyond a joke and you should be ashamed of yourself."
The two senators pushed for a "conference" between the two houses of parliament, which was last attempted in 1950 and hasn't succeeded since 1932.
A conference brings together delegates from both chambers to thrash out an agreement.
The motion passed the Senate 32 votes to 30, with the coalition and crossbench in support and government and Greens against.
However, attempts to allow the conference failed to get enough votes in the House of Representatives to get off the ground.
Mr Burke introduced new amendments to the wider bill in the lower house, despite it not being able to pass the Senate until at least February because a committee is examining it.
The government changes included exclusions for service contracting for labour hire loophole laws and additional guardrails for the Fair Work Commission when the body sets minimum standards for gig economy workers.
The definition of a casual employee will also be changed so that people who are employed in a regular pattern of work can still be deemed as a casual and not a part-time employee.
"The amendments are pragmatic, practical changes that ensure we avoid unintended consequences," Mr Burke said.
"They come after constructive consultation with employer groups and business - like Uber, Menulog, DoorDash, the Australian Hotels Association and the Australian Resources and Energy Employer Association.
"These organisations have come to the table to work with government and that means we now have better legislation."
The Greens have also secured amendments to three parts of the government's broader workplace bill.
Underpaying superannuation would be treated the same as wage theft, while teachers and lecturers could no longer be considered as carrying out seasonal work.
Greens leader Adam Bandt said the amendments did not mean the party would support the laws passing in the Senate.
He said the party would fight for the right of employees to disconnect from work.
"People should have the right to log off when they clock off ... you should be able, after hours, to ignore your boss's texts and emails unless you get remunerated for it," Mr Bandt said.
Independent MP Allegra Spender criticised the government for rushing more than 100 amendments through.
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Australian Associated Press