‘The second carrier is an asset that is held in reserve and is a very expensive piece of rarely-used equipment.

‘So if we want to address balance sheet issues, disposing of her or sharing her with say an AUKUS [Australia, UK and US] ally, is an option.’

Official sources said while the Navy remained committed to both carriers, ‘changes in government and budgets’ may alter this assessment.

Ministers have told top brass they must ‘spend better’ to convince the treasury to increase funding.

Retired Royal Navy Commander Tom Sharpe said: ‘If I was a carrier-sceptic, and there are plenty, I would be gunning for one of them right now.

‘It does not help their cause that when a near-perfect opportunity to use a carrier presented itself in the Red Sea, we didn’t take it for political reasons.

‘We must recognise the threat to the second carrier, that is the unpleasant reality; the nuclear deterrent is the UK’s only ring-fenced capability.’

The carriers were approved in 2007 by then prime minister Gordon Brown. One of them was almost scrapped before it even set sail, but ministers discovered axing it would actually be more expensive.

HMS Prince of Wales and HMS Queen Elizabeth cost a combined £7 billion. Today it is widely accepted the UK will not be able to adequately defend or operate them independently.

The service only has one solid stores ship, the RFA Fort Victoria, to support the carriers and she is due to be retired in 2028.

The 65,000-ton aircraft carriers and their strike groups have previously relied on protection from allies including the Netherlands and the US.