An inability to safely use lifeboats or life rafts was one of 31 failures discovered on a detained P&O Ferries vessel that linked Scotland to Northern Ireland.

An analysis by the Maritime and Coastguard Agency (MCA) found that the "launching arrangements for survival craft" on the European Causeway which operate were "not as required" while finding a raft of failings ranging form problems with fire safety to lifeboat drills.

The details emerged from the Paris Memorandum of Understanding (MOU) – an alliance of 27 national maritime authorities, including the UK – which listed the safety deficiencies but did not provide further details.

The ship has two lifeboats and several life rafts for use in emergencies.

Among other flaws identified by the MCA included inadequate fire prevention systems, an inflatable evacuation slide not properly maintained, and crew having a lack of familiarity with radio equipment.

Among seven key reasons given as ground for detention were a lack of familiarity over the operation of Global Maritime Distress and Safety System (GMDSS) equipment, the worldwide system for automated emergency signal communication for ships at sea.

There were also problems with missing documents relating to personnel and stability information and navigation.

The 22-year-old vessel which can carry up to 410 passengers, was detained on March 25 and released on April 8 after an examination.

Analysis revealed more failures were found than in any of the other 46,000 Port State Control inspections of ships within the Paris MOU in the past three years.

P&O Ferries was widely condemned after sacking nearly 800 seafarers without notice on March 17 and replacing them with cheaper agency staff.

The firm initially indicated that the Scottish services to Northern Ireland would be shut down for a week to ten days while they located new crew.

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The suspension also hit services between Dover and Calais,  Dublin to Liverpool and Hull to Rotterdam.

A total of eight P&O Ferries vessels will be probed by the MCA following the mass sackings.

The Spirit of Britain and Pride of Kent remain under detention after safety issues were found.

The Pride of Kent had 25 deficiencies, eight of which were serious enough to be grounds for detention.

The 30-year-old, Cyprus-flagged ferry had previously been inspected in August last year, when just eight deficiencies were found. In a possible sign of the increased scrutiny of P&O, one of the deficiencies found in both inspections was the fire detection and alarm system, judged “not as required”. Last year, however, it was not deemed a ground for detention.

Two failings were related to the new crew – a lack of familiarity with the machinery and a lack of training for the fire drills.

The Spirit of Britain, another Dover-based ship, has also since failed an inspection but details have not yet been released.

Pride of Hull passed its inspection, enabling it to operate between Hull and Rotterdam.

Four other ferries are also out of action as they have not yet been inspected.

A spokesman for P&O Ferries said: “Following confirmation from the MCA that the European Causeway is safe to sail, we were delighted to restart sailings between Larne and Cairnryan last week.

“P&O is pleased to play its part in supporting customers to move vital goods between Northern Ireland and Scotland.

“It is clear that inspections of our vessels have reached an unprecedented level of rigour.

“We welcome this additional scrutiny and would reiterate that the safety of our passengers and crew is our foremost priority.

“Any suggestion that it is being compromised in any way is categorically false and we look forward to all of our ships welcoming tourist passengers and freight customers again as soon as all mandatory safety tests have been passed.”

The MCA has said its inspections are conducted “in exactly the same robust way” for every ship.