Svitzer Australia has said it will lock out harbour towage crews from 17 ports in Australia indefinitely, in a major escalation of a long running dispute with unions.

The AP Moller-Maersk towage company said the action, which would affect 582 employees, will come into force on 18 November.

“The step was taken in response to industrial action which has made it difficult for Svitzer to run its operations,” the shipowner said.

“There is significant disruption and ongoing uncertainty about the availability and reliability of our workforce and the ability to deliver services.

“This is harming our ability to reliably, safely and efficiently serve our shipping customers and port operations nationally.”

Trade association Shipping Australia said it “supports Svitzer Australia in its efforts to resolve industrial dispute” which has been running for three years.

Svitzer Australia said there have been more than 1,100 instances of industrial action notified by the maritime unions since October 2020.

“Since 20 October 2022, there have been more than 250 instances of protected industrial action alone, amounting to nearly 2,000 hours of work stoppages,” the company said.

Workers at Svitzer are represented by three maritime unions, depending on the work performed: the Maritime Union of Australia (MUA), the Australian Institute of Marine Power Engineers (AIMPE) and the Australian Maritime Officers Union (AMOU).

Svitzer said it has had to respond to the protected industrial action as a “matter of necessity with one of the few avenues available to employers faced with such action”.

When the lockout becomes effective, no shipping vessels will be towed in or out of 17 Australian ports otherwise serviced by Svitzer.

This will impact shipping operations at major metropolitan and regional Australian ports nationwide in Queensland, New South Wales, Victoria, South Australia and Western Australia.

However, it will not affect Svitzer terminal operations supporting the oil and gas sector or operations in other states and territories.

Svitzer Australia managing director Nicolaj Noes said in a statement that he had hoped it would “never come to a lockout”.

“Our goal all along has been to reach a new enterprise agreement and we have exhaustively negotiated in good faith to try to do this,” he said.

“But we are at a point where we see no other option but to respond to the damaging industrial action underway by the unions.”

Maritime Union of Australia secretary Paddy Crumlin said the company was acting in bad faith.

“Now they’ve decided to take a militant national action of shutting down the country’s ports because I guess they’re big and powerful, they’re heading for a $30 billion profit this year, and I guess size doesn’t give you much moral energy,” he told Australia’s ABC News.