The CAA collect radio licence fees on behalf of, in effect, the Inland Revenue, but the only powers they have under the ANO in this instance would include reckless endangerment.
Whilst Sir George is correct up to a point, the CAA does (or certainly did a few years ago) have a bit more involvement with radio station licensing such as approval of callsigns, approval of frequencies for particular uses and services and the co-ordination of protected frequencies (i.e. assignments designed to try to minimise the likelihoon of interference from stations using the same frequency).