PROPOSED amendments to the Foreign Workers Bill could place growers under even further pressure.

The changes would require growers to sign contracts with labour hire agencies that foreign workers were permitted to work in Australia, thus taking more of the burden to ensure their employees are not working in Australia illegally.

This would mean responsibility would ultimately lie with the growers, not the hire companies.

As it stands the labour hire company is responsible for checking their employees have valid working visas.

The Migration Amendment (Reform of Employer Sanctions) Bill 2012 implements further recommendations from an extensive review by Stephen Howell last year.

It sets out penalties for bosses in breach of legislation, including infringement notices and search warrants.

Peak industry body AusVeg spokesman Hugh Gurney said to remain viable, the Australian vegetable and potato industries relied heavily on workers sourced through labour hire companies.

"The employment relationship that workers have is with the labour hire company and not with the grower, so it is reasonable to expect that labour sourced from these companies complies with all relevant requirements as part of their cost of doing business," Mr Gurney said.

"The onus should not be on the grower to do the labour hire company's job for them.

"Many growers have had to employ additional administration staff to deal with the red tape surrounding the employment of overseas workers."

AusVeg has made a formal submission to Immigration Minister Chris Bowen.

Mr Bowen said the amended Bill enabled "strong action if initial approaches involving education and targeted warnings fail to convince deliberately unco-operative employers that they are not above the law".

An Immigration Department spokeswoman said: "The amendments will only affect workers who aren't doing the right thing so they will not place further burden on growers."

She said employers had access to the online service VIVO visa entitlement, which allowed them to check if potential employees had workers rights.

The Bill is before Parliament.