The Nautilus International union is urging the British government to confirm UK seafarers will still be able to work on EU-flagged ships after Brexit.
It has written to minister of transport John Hayes to seek assurances on the recognition of crew certificates.
The action was prompted by the European Commission warning of ‘certain legal repercussions’ for the mutual recognition of certification arising from the UK becoming a "third country" in 2019.
The EC’s transport directorate said UK seafarer certificates will no longer be automatically recognised by the remaining 27 member states.
Existing UK certificates which have an ‘endorsement attesting recognition’ will continue to be valid until their expiry date, but will not be transferable between different EU flags, Nautilus said.
General secretary Mark Dickinson said: “We believe it is vital that the UK government takes steps now to provide our members with certainty for the years ahead and to ensure that Brexit does not create new barriers to their employment.”
Nautilus wants to know whether the UK government has plans in place to address the issue.
The union is also urging the minister to consider whether the future recognition of UK seafarer certificates could be part of any transition deal, and what contingencies are in place for a ‘no deal’ scenario.