Warning from farmers on workplace laws

The peak body for Australian farmers has warned changes to the country's workplace laws would impact grocery prices and essential supply chains due to increased strike actions.

The National Farmers' Federation told a Senate committee examining the new industrial relations laws that producers would be directly hit by the changes proposed.

The bill, which passed the lower house on Thursday, would enshrine multi-employer bargaining, as well as aim to lift the rate of pay in feminised industries.

The federation's workforce committee chair Tony York said the farming sector had faced challenges in recent years in getting enough labour.

While the federation welcomed parts of the law changes, Mr York said small businesses could be forced into new agreements, which could affect the agricultural sector.

"We are most concerned effectively about the potential for widespread industrial action shutting down supply chains and processing sectors, they are of direct consequence to farmers," Mr York told the committee.

"It's not just a monetary consequence, you'd lose the opportunity to have continuity of supply ... and there's even animal welfare issues that can come into effect if we have widespread strike action."

Such strike action would also lead to higher prices at the supermarket checkout for groceries, the federation warned.

The peak body also criticised the time frame for the bill's examination, saying more time was needed for the full effects of the laws to be scrutinised.

"I do think that the government is treating the parliamentary processes with some degree of contempt by rushing this through," Mr York said.

However, the committee's chair, Labor senator Tony Sheldon, hit back saying the fears of strike were nothing but hysteria and a scare campaign.

"The track record of (the agriculture sector) in dealing with minimum wages in various sectors of this industry has been appalling," he said.

"You tend to have some very definitive views about the legislation for somebody that doesn't have a view about the legislation because you don't know what's in it."

Master Builders Association deputy chief executive Shaun Schmitke told the inquiry the laws would take power away from workers.

"Master Builders does not support any law or change to workplace law that gives unions more of a right or more of a say over the conditions of employment than the actual workers to whom those conditions will apply," he said.

"We're never going to support laws that take the enterprise out of enterprise bargaining ... We don't want to open the door for a return to industrial ideals or industry-wide strike action."

Mr Schmitke said the laws required a rethink.

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 report just before the final sitting fortnight of the year starting on November 21.

Deputy Prime Minister Richard Marles said the government had a mandate to implement the reforms quickly.

"This is legislation which makes industrial relations fairer in the workplace and encourages employers, their workers, unions, employer organisations to get round the table to get better, more productive deals going," he told the Nine Network.

Opposition Leader Peter Dutton said the laws would reduce the ability of small businesses to negotiate with employees.