The most senior civil servant at the MoD has told MPs it would be "perfectly reasonable" to cannibalise parts from Britain's second aircraft carrier, HMS Prince of Wales.
Mr Lovegrove was asked if he could guarantee that HMS Prince of Wales would not be cannibalised to support HMS Queen Elizabeth.
He told the Public Accounts Committee that if it meant one aircraft carrier was able to stay at sea and the deployment pattern was not going to be affected, then "why wouldn't you?".
He said: "I wouldn't rule out the chances of that, there are certain bits of equipment on the Prince of Wales which may find themselves being repurposed for use on the Queen Elizabeth.
"I think that would be potentially a perfectly reasonable thing to do if it were not to compromise the operational schedules of either of the two boats."
HMS Prince of Wales was floated for the first time last month and is currently being fitted out, while HMS Queen Elizabeth is in Portsmouth undergoing repair work to a seal before continuing trials.
Last year, an investigation by the National Audit Office (NAO) discovered that the Royal Navy is being forced to strip parts from its vessels in order to maintain its fleet of ships and submarines.
The practice has increased 49% from 2012 to 2017 and the spending watchdog said budget cuts in the last two years could be the cause.
Rear Admiral Richard Stokes defended the procedure of moving parts across the Royal Navy’s fleet, he described it as a "valid method for protecting the programme of the highest priority operating units".
The NAO report also describes the practice as an effective way to keep vessels operational during high-intensity operations.
However, it can also cause increased costs - in 50% of cases involving Type-23 frigates the cost of moving the part between ships was equal to or greater than the value of the part in question.
Mr Lovegrove told the committee that if spares were to be held in stock, it would require a further £920 million of "capital tied up” which “doesn't make sense".
Astute-class Submarines and Type 45 Destroyers Most Affected
Nuclear-powered Astute-class submarines experienced the most cannibalisation in the fleet with 59 instances per boat on average.
Type-45 destroyers, which have been plagued by problems, were partly responsible for the increased level of cannibalisation. 44% of the cannibalisations reported involved either Astute-class submarines or Type-45 destroyers.
Mr Stokes told the committee that the reliability issues of the Type-45 was due to being built with "80% new equipment".
He said that as the technology on the ships is more widely understood, there will be less need for parts to be cannibalised.
The "Demotivating" Impact Of Ship Cannibalisation
The report highlighted the "demotivating" impact cannibalisation could have on sailors who have to deal with the issues regularly.
Mr Lovegrove said that there are times when that happens, particularly across the Astute-class and Type-45 platforms.
He said he is "not uncomfortable" with the level of cannibalisation, and said the NAO's report was "extremely helpful".
"It has shone a very helpful light on some of the ways in which we go around managing our maintenance schedules and our stores.”
"The area where I would like the teams to concentrate more are on the parts which are repeatedly cannibalised because that would indicate we are getting something not quite right in that area."