A P&O ferry has been detained in Northern Ireland “due to deficiencies in crew familiarization, vessel documentation and crew training”, according to the Maritime and Coastguard Agency (MCA).
The agency said the ship, the European Causeway, was seized at the port of Larne.
Transport Secretary Grant Shapps said the ferry was stopped for “unfit to navigate”.
Shaps wrote on Twitter“Following my instructions to inspect all P&O vessels before returning to service, the MCA has detained one vessel for unseaworthiness. I will not compromise the safety of these vessels and P&O will not be able to rush the training of inexperienced crews.
MCA said: “The vessel will remain in detention until all these issues are resolved by P&O Ferries. Only then will it be re-inspected.
The detention of the ships is based on concerns about their safety and to prevent them from going to sea.
Karl Turner, Labor MP for Hull East, wrote on Twitter: “Things are getting worse for P&O Ferries, news being just that the European Causeway on the Cairnryan-Larne route has failed its Port State inspection.
“The vessel is arrested and detained by the Larne Maritime and Coastguard Agency.”
Earlier this week, an inspection was carried out by the MCA on a P&O ferry docked in Hull to ensure that agency staff brought in to replace 800 laid-off workers can operate it safely.
Downing Street has called on the chief executive of P&O Ferries to resign over the sacking of staff and pledged to push through legislation next week to force the company to reverse its decision and pay its crew the minimum wage.
Peter Hebblethwaite admitted to MPs on Thursday that his company broke the law by firing the 800 workers without consultation.
Transport union RMT said it welcomed the detention of the European Causeway and demanded the government “seize the entire fleet” of P&O ships.
General Secretary Mick Lynch said: ‘MCA’s takeover of the European Causeway this evening shows that the capitalist gangster P&O group is not fit and proper to run a safe service after the jobs massacre.
“This crowd should be banned, their vessels seized and the laid off crews reinstated to get these crucial ferry routes running safely again.”
Alliance MP for East Antrim Stewart Dickson welcomed the impoundment of the ferry as a safety measure.
“It’s not like the crew of a plane getting off an easyJet and moving on to the next one where the controls are exactly the same and everything is in the same place,” he told PA.
“No two ships are the same, and you can’t just bring in a crew and expect them to be able to pilot a ship. Every check will be at a different location, but in particular every health and safety drills that need to be done, from the lifeboat stations to the operation of every piece of equipment, it seemed to me that it was going to be very difficult for the staff to be able to take on this role in such a short time.
“I am absolutely thrilled that they have [impounded the ship]. It’s not revenge against P&O, it’s a matter of passenger and crew safety as well.