A P&O Ferries ropax has been detained in Northern Ireland after UK authorities deemed the vessel “unfit to sail”.

The 20,600-gt European Causeway (built 2000) was detained due to “failures on crew familiarisation, vessel documentation and crew training”, the Maritime and Coastguard Agency (MCA) said.

“The vessel will remain under detention until all these issues are resolved by P&O Ferries. Only then will it be reinspected,” the MCA said.

The MCA added that there were no passengers or freight on board the European Causeway when it was detained.

UK Transport Secretary Grant Shapps took to social media to confirm the detention of the Bahamas-flagged vessel.

“Following my instruction to inspect all P&O vessels prior to entering back into service, the @MCA_Media has detained a ship for being unfit to sail,” he said on Twitter.

“I will not compromise the safety of these vessels and P&O will not be able to rush inexperienced crew through training.”

The RMT union said it welcomed the detention of the European Causeway and it demanded the government “seize the entire fleet” of P&O vessels.

General secretary Mick Lynch said: “The seizing of the European Causeway by the MCA shows that the gangster capitalist outfit P&O is not fit and proper to run a safe service after the jobs massacre.

“This mob should be barred, their ships impounded, and the sacked crews reinstated to get these crucial ferry routes back running safely.”

P&O, which is owned by ports giant DP World, is currently involved in a major labour dispute after it sacked almost 800 seafarers and announced plans to replace them with agency staff on cheaper salaries.

British Prime Minister Boris Johnson has backed calls for P&O Ferries’ chief executive Peter Hebblethwaite to quit over the sacking of workers without notice.

Louise Haigh, the shadow transport secretary for the UK’s opposition Labour Party, posted on social media: “The trained, experienced, loyal crew should be reinstated. And the chief executive should be barred as a director.

“The shameful misconduct of P&O Ferries has ruined livelihoods and is harming the UK’s key shipping routes.”