Rotterdam port workers are planning to take industrial action in their efforts to get job guarantees following the opening of a new extension.

The Tweede Maasvlakte section of the port is largely automated and unions are demanding job guarantees for the next nine years. The port authority says this is too expensive in the face of growing competition from Antwerp and Hamburg.

Some 850 port workers attended a packed meeting on Monday night and the overwhelming majority voted in favour of industrial action, local broadcaster RTV Rijmond said.

If the plan goes ahead, three-day campaigns will take place in December and January and all-out strikes have not been ruled out, the FNV trade union said.