Britain's most modern warships have suffered more than 5,000 defects since launching, Government records show.
The Type 45 destroyers, which cost £1 billion each, are due to undergo major refits, with holes cut in their sides to fit them with new engines as they keep breaking down.
And new Ministry of Defence (MoD) figures have shed further light on the extent of the problems experienced by the Royal Navy ships, which are used to support international operations against so-called Islamic State, provide humanitarian aid and to hunt pirates.
Shadow defence secretary Emily Thornberry warned the "deeply troubling" figures suggest the Government has a "laissez-faire attitude" to the safety of the Navy's fleet.
The MoD data shows HMS Daring recorded 967 operational defects between 2011 and 2015.
From 2012 to 2015, HMS Dauntless sustained 895 defects, HMS Dragon 887, HMS Defender 844 and HMS Diamond 818.
HMS Duncan recorded 590 defects from 2013 to 2015, bringing the overall total for the six ships to 5,001.
Separate MoD figures also record maintenance and repair costs for the six ships of £51 million.
Labour's Ms Thornberry said: "Our six destroyers are often referred to as the backbone of the Royal Navy.
"We send them all around the world on dangerous operations, including in the Gulf, where half the fleet was deployed last year.
"So it is deeply troubling that the ships are still experiencing hundreds of technical faults every year, including, in some cases, complete power cuts.
"The MoD has been aware of these problems for years, but despite spending more than £50 million on maintenance and repair, ministers appear to be no closer to resolving the underlying issues.
"The Government's apparently laissez-faire attitude to the safety of the Navy's fleet is simply unacceptable."
The figures emerged following written parliamentary questions from Ms Thornberry.
Defence Minister Philip Dunne, in reply to the questions, told Ms Thornberry: "All complex systems suffer defects and require maintenance throughout their life, and warships are no exception.
"Operational Defects (OPDEFS) can vary in their categorisation and severity, covering minor ancillary components to major defects.
"The OPDEF process only applies to ships in operational service, and I have therefore supplied the numbers for full years for Type 45 ships since their commissioning."
He added: "We would not release more detailed information related to these figures as this would allow deductions to be made about a ship's capability and may affect operational security."
The MoD confirmed in January the engine repair work for the six Type 45 destroyers.
The work is expected to be staggered over a period of years so some ships remain available for operational commitments at all times.
In 2014, HMS Dauntless had to abandon a training exercise and in 2009 HMS Daring lost power in the Atlantic on her first voyage to the US.