The national maritime union and an associated labour hire firm have been ordered to pay a Perth couple more than $720,000.

The record payout was awarded after the Federal Court found Offshore Marine Services (OMS) and the Maritime Union of Australia guilty of breaching the Workplace Relations Act.

The union and OMS (now called Skilled Offshore) refused to give a Perth couple jobs because they were not union members.

Justice John Gilmour found that the MUA’s conduct “involved its blatant use of illegitimate industrial action power to bully OMS” into refusing to employ the couple.

The MUA’s actions deprived the couple of the opportunity to gain well-paid employment “at a critical time of their lives”, Justice Gilmour said.

He said that OMS “succumbed” to union threats of industrial action, even though it wanted to employ the couple.

WA residents Bruce and Lynne Love were awarded $352,100 and $371,200 respectively, after being promised offshore jobs as a steward and a cleaner in 2009.

The couple were told they had to complete training and join the union before they were sign up officially, so they borrowed money for the training course and tried to join the union twice, but were denied.

“It was so frustrating because it was like standing two inches from the golden chalice and then watching it disappear into the sunset,” Mr Love told reporters for The West Australian.

“I couldn't believe this kind of union thuggery could happen in this day and age.”

The union was ordered to pay two-thirds of the compensation and an extra $79,200 for its role, while OMS is liable for a third of the compensation.

MUA boss Christy Cain said union lawyers would now look at the decision and determine their next step.

Minister for Employment Senator Eric Abetz said: “This behaviour is completely unacceptable and comes from union bosses who proudly boast that ‘laws need to be broken’”.