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.