The leader of the RMT union is set to say that a vote to leave the EU this June is essential to save CalMac ferry services from privatisation.
Mick Cash, the union’s general secretary, will make the call at a meeting at the Scottish TUC’s annual congress on Monday evening.
The result of the Scottish Government’s tendering process for the next Clyde and Hebrides Ferry Service (CHFS) contract is expected to be revealed next month - after the Scottish Parliament elections on May 5, but before the EU referendum on June 23.
Mr Cash said: “For some time now we have been arguing that the Scottish Government should stand up for Scotland and should stop the tendering of life line ferry services.
“To date they have continued to carry out the instructions of the EU but it is difficult to see how they can conclude the EU driven ferry tendering process prior to the referendum result.
“That means the referendum provides an opportunity to save our ferry services from this EU-directed privatisation.”
Two firms - the state-owned incumbent, CalMac Ferries Ltd, and private sector rival Serco Caledonian Ferries Ltd - have submitted bids for the next CHFS contract, which carries with it a subsidy of more than £1 billion.
The new contract begins in October and is due to last for eight years.
Mr Cash said the EU was “no more than a corporate cabal run for the benefit of corporations like Serco”.
“People should be in on doubt that if Scottish ferries end up being privatised the Scottish Government will have pulled the trigger and the EU will have provided the gun,” he added.