There is an unspoken value to the RN having even just one supercarrier. If the Brits began to build one, the French would have to match it. And, with French arrogance, corruption, silliness and ineptitude, the project would break the country financially and still be a failure. The carrier they just build has had failure after failure, a great wine cellar but a lousy propulsion system. The French would turn a 3 to 10 billion dollar project into a 20 billion dollar project, make Chirac and his mistress even wealthier, but still wouldn't work on the high seas. So, go get 'em Brits, let's bankrupt the froggies!
The french already have a "supercarrier." Of course, after the propeller fell off and the washing machines threatened make the poor thing disintegrate, they haven't used it much.
Err,The French are building a conventionally powered cousin to the Charles DeGaulle(guess they learnt their lessons).It will be around 40,000 tonnes in displacement & will be ready by the time the 2 Brit carriers hit the oceans. & IIRC,both Britain & France have agreed on technology cooperation to reduce cost & time!!!