Tugboat engineers have launched strike action across the country over moves to change their employment awards.

Work stopped on Tuesday morning for Svitzer employees at the ports of Newcastle, Sydney and Geelong, with 12 hour stoppages intended to send a message as negotiations for a new enterprise agreement go nowhere.

Further strike action is planned in Brisbane and Melbourne this week.

Svitzer is looking to move the engineers under the same agreement as deckhands and tugboat skippers - a move the company says is aimed at rationalising existing agreements.

“As it currently stands we have three crew members on a tug, and they're covered by three agreements, and we have to deal with three unions at a time to get anything done, and we think that in the 21st century it just makes sense to have a single agreement covering all three people on that tug,” Svitzer spokesperson Craig Carmody said.

But the union responsible - the Australian Institute of Marine and Power Engineers – says it will hold its ground while working with port authorities.

“The issue is one of great concern to them, however in terms of impact, we gave notice last Wednesday, six days ago,” union rep Martin Byrne said.

“The arrivals and departures in the Port of Newcastle have been rescheduled so as to avoid a clash with the 12-hour stoppage that's been notified.”