Measures to make it easier to employ foreign workers on offshore facilities have been ruled invalid by Australia’s Federal Court after an appeal by the maritime union, reports abc.net.au.

In 2014, the Federal Government attempted to override the Senate and change visa regulations via a ministerial determination to make it easier to employ overseas workers on offshore oil and gas projects.

Today the Maritime Union of Australia (MUA) won a Federal Court appeal in Sydney, overturning a previous court decision to dismiss their appeal. A three-judge panel has allowed the appeal and agreed that the legislation could not be used in the way that it had been.

It said the determination by Assistant Immigration Minister Michaelia Cash "is not authorised ... and is invalid."

The judgment read: “The Parliament's intention was to confer upon the Minister a power to except or exempt particular activities or operations carried out under the Offshore Petroleum Act or Offshore Minerals Act, not to reverse the Parliament's desire and intention to bring within the [Migration] Act non-citizens who are engaged in operations and activities under the Offshore Petroleum Act or the Offshore Minerals Act.”

The previous Labour government had amended the Migration Act to extend the migration zone so that foreign workers needed a permanent visa to work on offshore oil and gas platforms.

In May 2014, the Abbott Government introduced new regulation that would have allowed three existing temporary visa types to conform to the amended act, thus negating the need for a permanent visa.

However, that regulation was disallowed by the Senate.

In July 2014, Senator Cash issued a legislative instrument invalidating the amendments to the act. But the MUA claimed in court the Federal Government did not have the power to use the legislative instrument in that way. The MUA said the changes would have opened the door to cheap foreign labour.

Outside court MUA Deputy National Secretary Mick Doleman said there were more than 400 foreign workers on offshore oil and gas projects and they were potentially employed illegally and potentially underpaid.

He said the union did not necessarily want the workers removed from Australia but there was a need to make sure they were being paid Australian wages and were legitimately filling a skills shortage: "We don't believe that's the case.”

“The judgment absolutely vindicates the Maritime Union and the Australian Maritime Officers Union and the Senate in this country, who took a decision to reject the regulations that the Government was bringing in. So it's a fantastic outcome.”

"They had no regard to what the real circumstances were in the offshore oil and gas industry. They disregarded the Upper House of the Senate. We put a message out to the Government now that here's an opportunity to sit down with the unions and employers and develop a migration and work visa network and system that is robust and that does not exploit those workers and does have regard to serious and real short-term needs and skills in the offshore.”

"Not to just have this open slather where employers use the lowest common denominator to exploit these workers," Mr Doleman concluded.

It is not yet known if the Federal Government will go to the High Court to appeal against today's ruling.