HMS Queen Elizabeth and Russia
The British aircraft carrier HMS Queen Elizabeth is pulled from its berth by tugs before its maiden voyage, in Rosyth, Scotland, Britain Russell Cheyne/Reuters

Retired RAF leaders have sounded the alarm that the state-of-the-art vessel HMS Queen Elizabeth may be useless in any future conflict unless more more patrol planes protect it.

The new warship costing £3bn is the pride of Britain's Navy and has earned Defence Secretary Sir Michael Fallon bragging rights in his asides about the UK's naval capabilities compared with those of Russia.

However four former RAF officers have said that the nine Boeing P-8 submarine hunting planes planned to protect the ship are three short of what is required.

The UK's axing of its Nimrod patrol plane programme in 2010 has led many to claim there is now a shortfall of British aircraft capability.

In a letter to the Telegraph, the RAF men write that nine "exceptionally long-legged" Nimrod MRA4s previously planned, which could last 10 hours on task at 1,000 nautical miles from base, could have provided adequate cover for both the UK deterrent and one of our aircraft carriers, "but only just".

"This will not be the case with only nine P-8s (less than seven hours on task at that range)," the letter said.

"If HMS Queen Elizabeth is not to go straight to the bottom of the ocean as soon as hostilities break out, at least three more P-8s will be needed. Failing that, air-to-air refuelling must be made available by fitting refuelling booms to our A330 Voyager tankers," according to the Telegraph.

There has been considerable criticism at the cuts to Britain's maritime patrol planes, which came at a time when Russia stepped up its submarine activity in the North Atlantic.

HMS Queen Elizabeth is starting trials in the North Sea and would not be sent on operations until 2021 when it will be protected by a frigate and destroyer escort, F-35B jump jets and the new patrol planes.

But a new report from the Royal United Services Institute (RUSI) this week pointed to great gains made in military capability by China and Russia, which has closed the gap on Western military dominance.

The report said that cheap missiles costing less than £500,000 could disable the multi-billion pound vessel.