The Royal Navy's multi-billion-pound flagship won't sail after crew members tested positive for covid-19.
The £3billion HMS Queen Elizabeth, which was mainly built at Scots shipyards, was due to leave Portsmouth Historic Dockyard today for training exercises.
But the departure was put on hold at the 11th hour.
A Ministry of Defence spokesman confirmed that "fewer than 10" members of the 1,000-strong crew had tested positive for the coronavirus and had been taken ashore to be put into isolation in barracks.
Other sailors who had contact with their infected crew-mates will isolate on board the 65,000 tonne ship which is expected to leave Portsmouth as soon as Tuesday.
It is the second time the carrier has had to postpone its sailing after two crew members tested positive for Covid-19 in April.
A Royal Navy spokesman said: "A small number of HMS Queen Elizabeth's personnel have tested positive for Covid during routine preparation for sailing.
"Those affected have been isolated and are working with the NHS Test and Trace system to ensure the virus does not spread further.
"The crew will continue to follow appropriate health guidelines and the HMS Queen Elizabeth will depart once their status has been confirmed."
The spokesman said that the decision when to sail would be left to the carrier's commanding officer Captain Angus Essenhigh who will act on PHE guidance.
The carrier is expected to carry out training exercises at sea before returning to base for supplies ahead of departing for major international exercises including the embarkment for the first time of both US and UK F35 Lightning jets.
It is aiming to declare strike carrier capability later this year ahead of its first operational deployment in 2021.
