When might Britain begin a light fleet carrier programme?

Would Britain build light fleet carriers for itself and the Dominions?

A programme becomes plausible around 1943 if the war continues and creates demand for more carriers.

The estimate ties lighter carriers to wartime expansion after the conflict has begun. It does not assume a large peacetime programme already completed in 1942. Although the question mentions Dominion use, the reply does not assign ships to particular navies.