The Rail, Maritime and Transport (RMT) union is planning to blockade the Cairnryan port to protest over the sacking of hundreds of staff by P&O, the body’s Scottish organiser has said.

Gordon Martin said the union would hold a demonstration at the port on April 8, asking hauliers not to cross the picket line.

He addressed the spring conference of the Alba Party in Glasgow, saying that on Monday the union would also hold a protest at the offices of Clyde Marine Recruitment – accusing them of recruiting staff to replace the sacked workers.

A number of demonstrations have already taken place at ports around the UK amid calls for P&O’s chief executive to quit.

Mr Martin told the conference: “We’re going after the supply chain, we’re going after P&O and we’ll go after everybody.

“Because this will be a fight to the finish. If we lose, all you guys lose as well.

“Everybody loses if the bandit capitalists win. ”

He added: “On April 8, we’re going to go back to Cairnryan to blockade the port.

“Ask the hauliers and others not to cross our line. If you cross our line, we lose.

“If we lose, everybody loses.”

Mr Martin also spoke about the two ferries being built at the Ferguson Marine shipyard which have been heavily delayed.

Earlier in the week, an Audit Scotland report set out a “multitude of failings” which led to the cost of the ferries more than doubling.

Mr Martin said: “We need new tonnage. We’ve got a couple of boats lying in Ferguson Marine and I think I’ll be retired and long gone before they ever see a scrapyard somewhere.

“Because I don’t think they’re going to ever be on the water is my honest opinion.”

Clyde Marine Recruitment has said it had no prior knowledge about the mass sacking on Thursday last week.