The Royal Navy's flagship HMS Queen Elizabeth's departure to lead the largest NATO exercise since the Cold War has been cancelled at the last minute after an “issue” with a propeller shaft was spotted during final checks.
The setback comes some 18 months after sister ship HMS Prince of Wales broke down off the isle of Wight after she sailed for the US having suffered a malfunction with a coupling on her starboard propeller.
HMS Prince of Wales will now be made ready to take the place of the £3bn fleet flagship on the major exercises which will involve more than 40 vessels.
Fleet Commander Vice Admiral Andrew Burns said: Routine pre-sailing checks identified an issue with a coupling on HMS Queen Elizabeth’s starboard propeller shaft. As such, the ship will not sail on Sunday.
HMS Prince of Wales will take her place on Nato duties and will set sail for Exercise Steadfast Defender as soon as possible.
The UK is expected to send 20,000 military personnel to take part in Exercise Steadfast Defender 24.
Personnel from the Royal Navy, the British Army and the Royal Air Force are set to deploy across Europe alongside 31 Nato allies and Sweden as the alliance practices repelling an invasion by Russian forces.
A Ministry of Defense spokesman said the issue on HMS Queen Elizabeth was separate and not linked to the earlier defect on her sister ship.
He said: The issue identified is with the ship's shaft couplings. The ship's propeller shafts are too big to be made from a single piece of metal, so each shaft is made from three sections, which are connected using shaft couplings, which bind the shaft sections together.
HMS Prince of Wales broke down as she was heading to a diplomatic mission to carry out exercises with the US Navy, the Royal Canadian Navy and the US Marine Corps.
The carrier came to a halt off the Isle of Wight and was brought under tow back into the harbor for the problem to be identified.
Inspections by divers and engineers found the Nato flagship's 33-ton starboard propeller – the same weight as 30 Ford Fiesta cars – had malfunctioned, with a coupling holding it in place breaking.
HMS Prince of Wales was taken to the Babcock shipyard where she was built in Rosyth to undergo repairs to the propeller shaft, which took nine months to complete.
On that occasion, HMS Queen Elizabeth acted as the replacement for her sister ship on the US deployment.
More than 2,000 friends and family gave the biggest welcome to HMS Prince of Wales when she returned to Portsmouth in December.
Having HMS Queen Elizabeth out of action could affect the ability of the Royal Navy to deploy an aircraft carrier to the Red Sea amid the continuing threat by Iran-backed Houthi rebels, which Armed Forces Minister James Heappey suggested was being considered.
Announcing the carrier's sailing, Commodore James Blackmore, Commander UK Carrier Strike Group, said: Steadfast Defender demonstrates the unity of the alliance, our commitment to it – and that the UK continues to play a leading role in Nato.
The exercise allows us to train with our neighbours in a truly challenging environment, especially at this time of year – but that is why we have to operate up there; the weather cannot put us off.
Before heading to the Arctic, the Carrier Strike Group was due to take part in the annual Joint Warrior exercise off northern Scotland before joining Exercise Nordic Response – the maritime part of Steadfast Defender.