
Britain's six Type 45 destroyers, described as the backbone of the Royal Navy, spent 80 per cent of last year in dock.

The ships, costing £1billion each, need a multi-million pound refit after repeatedly breaking down in the Persian Gulf. But the work is not due to start until 2020.

Two of the cutting-edge warships, HMS Dauntless and HMS Defender, did not go to sea at all during 2017 – which had been hailed by officials and ministers as 'the year of the Navy'.

All six warships, which entered service from 2008, were made with an engine system which cuts out in warm seas, leaving sailors stranded for hours in total darkness.

Britain's six Type 45 destroyers, described as the backbone of the Royal Navy, spent 80 per cent of last year in dock

This led to fears that these key vessels – designed to shield the rest of the fleet from air or missile attacks – had become 'sitting ducks'.

HMS Dragon spent 309 days in Portsmouth last year, followed by HMS Daring with 232 days and HMS Diamond with 203.

HMS Duncan spent the most time at sea, but was still in dock for 197 days.

From January to March this year, HMS Daring, HMS Dauntless and HMS Defender have not left port.

Shockingly, engine-makers Rolls-Royce claim the Ministry of Defence did not tell them the 8,000-ton vessels would spend long periods in warm waters so they were not designed to operate in the heat.

All six warships (pictured in dock), which entered service from 2008, were made with an engine system which cuts out in warm seas, leaving sailors stranded for hours in total darkness

Insiders say a shortage of manpower, Christmas leave for sailors and routine maintenance had also been factors that kept the ships at Portsmouth.

Lord West, former head of the Navy, said: 'It is a disgrace that work on these ships has not been done as a matter of urgency.

'We have so few frigates and destroyers that we should have moved heaven and earth to get the work done.

'If there was a national emergency we can't rely on them.'

Whitehall sources, who blame the delays on cuts in maintenance contracts, say Defence Secretary Gavin Williamson has since ordered deployments and four of the ships are currently at sea.

However, last December Britain had no major warships on operations anywhere in the world for the first time in living memory.

HMS Duncan spent the most time at sea, but was still in dock for 197 days

The absence of any of the Navy's 19 frigates and destroyers overseas was described as a 'strategic embarrassment for the country'.

Defence ministers and service chiefs are pushing for more spending after years of cuts and a budget review is now underway.

The problem first became public knowledge in 2016 when it emerged that two Rolls-Royce turbines on each ship slow down in warm waters and the engine fails to generate enough power.

The system does not recognise this and 'trips out' the ship's generators, resulting in total electrical failure.

The problem does not occur in the North Sea because the engine can generate more power in colder temperatures.

Two of the cutting-edge warships, HMS Dauntless and HMS Defender (pictured), did not go to sea at all during 2017

The MoD has set aside £160million to correct the problem by installing extra diesel generators to enhance the power and propulsion systems.

This could involve cutting a giant hole in the side of each ship but work on the first one is not due to start until 2020, followed by sea trials a year later.

An MoD spokesman said last night: 'The Royal Navy has a truly global presence with 25 ships and submarines currently at sea.

'Since 2016, our Type 45 destroyers have proved indispensable on global missions to protect commercial shipping in the Gulf, support coalition attacks on Daesh (ISIS), prevent the smuggling of weapons into Libya, and lead the NATO maritime task force in the Black Sea and Mediterranean.'