A dozen workers at Norway’s Mongstad oil refinery could go on strike if an upcoming round of wage talks fails to result in agreement, Norway’s Safe labor union said Jan. 15.

No date has yet been set for the negotiations, which will be led by a government-appointed mediator.

In case of a protracted conflict, a strike could also spread to other onshore facilities, with as many as 800 oil and gas workers potentially involved, the union said.

Equinor’s natural gas processing plants at Kaarstoe and Kollsnes could be affected, as could the Sture oil export terminal and the onshore control rooms of the Valemon and Martin Linge oil fields.

Workers at Exxon Mobil Corp.’s Slagentangen refinery could also be affected, along with employees at Lundin Energy, Wintershall Dea, KCA Deutag and Alexela Sloevag, Safe said.

Equinor did not immediately respond to a request for comment.

The Norwegian Oil and Gas Association, an industry group, was not immediately available for comment.