The UK’s new aircraft carrier, HMS Queen Elizabeth, is leaking because of a faulty seal.
The Royal Navy’s future flagship, which was commissioned by the Queen earlier this month, has a problem with one of its propeller shafts.
The fault on the £3.1bn carrier was first identified during sea trials.
A Royal Navy spokesman said the ship is scheduled for repair and the fault does not prevent her from sailing again early in the new year.
BBC defence correspondent Jonathan Beale said the problem was “highly embarrassing” for the Royal Navy and was just one of a number of snags still to be rectified.
A Royal Navy spokesman said: “An issue with a shaft seal has been identified during HMS Queen Elizabeth’s sea trials; this is scheduled for repair while she is alongside at Portsmouth.
“It does not prevent her from sailing again and her sea trials programme will not be affected.”
News of the leak comes after MPs raised concerns over the costs of the F35 jet aircraft which will fly off the carrier.
The Commons defence select committee said there has been an “unacceptable lack of transparency” over the jets with one estimate suggesting each plane will cost more than £150 million.
The 900ft-long (280m) carrier cannot currently deploy planes but the Lightning fighter jets are due to make their first trial flights from the carrier’s deck next year, with 120 air crew being trained in the US.
The UK has begun a £9.1 billion programme to buy 48 of the F-35s by 2025 from US giant Lockheed Martin.
Defence committee chairman Julian Lewis said: “F-35 is a major investment for the UK and we want it to succeed for the good of this country’s security.
“However, it is precisely because this project is so important that it must be subjected to the closest possible scrutiny.”