A strike that could hold up millions in resource export has been delayed, because the organisers accidentally scheduled it at the wrong time.

The strike is still planned at the Port Hedland port even though it was aborted at the last minute.

The industrial action was stopped short after a union realised it had mistakenly scheduled it outside a protected action period.

It is the result of an ongoing stand-off between tugboat engineers and their employer, Teekay Shipping.

The workers want their hours capped at 12 a day and a 3.5 per cent pay rise on their base salary of $225,000 a year.

The engineers are in charge of technical operations on board the tugboats, which guide giant iron ore cargo ships in and out of Port Hedland. They must be qualified as engineers and have several years of experience at sea.

They had been planning to strike as negotiations over new contracts fall apart, but the Australian Institute of Marine and Power Engineers says it has now been delayed.

Senior national organiser Andrew Williamson says the strike was called as a 30-day protected strike period expired, which would have meant tugboat engineers could only legally strike for one day.

“The easiest thing for the union to avoid litigation is to re-ballot the members,” he said.

The union is required by Federal law to give at least three working days notice before any action, and Teekay Shipping has now leapt on the blunder and threatened a court injunction to stop it.

The tugboat engineers strike will affect the $100 million-a-day iron ore transfer.