Britain must have two working aircraft carriers if it wants to be a global military player, a Foreign Office parliamentary aide has said.
A Government cost-cutting proposal to mothball or sell one of two carriers being built would be a poor use of public money, Tobias Ellwood MP said in a report for a military think tank.
Trying to rely on a single carrier would also undermine the UK’s ability to cope with international crises.
Mr Ellwood said: “The UK either needs a carrier capability or it does not.
“If it does, then a minimum of two are required in order to have one permanently available.”
Running both carriers would cement Britain’s position as “a global player with a military power of the first rank,” he said.
The Government has yet to decide the fate of the two 65,000 ton Queen Elizabeth class carriers currently being built, but the 2010 defence review proposed selling one or keeping it mothballed to save money.
Mr Ellwood, in a report for the Royal United Services Institute, said: “A £3-billion carrier waiting in ‘suspended animation’ in Portsmouth to be activated has political consequences, as does the selling of a ship at a loss.
“Neither option is a sensible use of taxpayers’ money. Indeed, the latter should be firmly disregarded.”
He said the lack of British carriers during the 2011 Libya campaign had meant that RAF Tornadoes and Typhoons had been forced to fly a 3,000 mile round trip from the UK to hit Col Gaddafi’s forces.
Even when a base became available in Italy, he said air raids were still four times more expensive than if they had been launched from a carrier in the Mediterranean.
Mr Ellwood, a former Army officer, said: “The carrier’s agility and independence means it is likely to be one of the first assets deployed to any hotspot around the globe.”
He said a single carrier would only be available around 200 days per year because of maintenance work.
Last week backbenchers on the Public Accounts Committee warned the aircraft carrier programme faced further spiralling costs.
The project remained a “high risk” because technical problems had not been resolved and there was potential for “uncontrolled growth” in the final bill.
The committee also said a decision to change the type of planes to fly from the carriers had wasted tens of millions of pounds.
The Ministry of Defence had originally opted for jump jet versions of the F-35 Joint Strike Fighter, then switched to the carrier variant, only to return to the jump jets again last year when costs soared.
Philip Hammond, Defence Secretary, said no decision would be made on what to do with the two carriers until the 2015 strategic defence and security review.
But money saved by reverting to the jump jet F-35s meant there was the possibility of having two operational carriers.
He said: “Of course there are operational cost implications of holding two carriers available rather than one, but we will weigh very carefully the benefits of that and the costs of that in the review.”