Although now the old class B licence is regarded as a full licence, it never use to be, as the B licensees did not hold a Morse code pass & thus could not legally use HF, so clearly they were not a full a licensee, or not as full as the old A class licensees who could use HF & had passed an extra & mandatory test to use HF.
It also shows how Ofcom can & does only act on the Wireless Telegraphy Act as & when it suits them. As they are not revoking any unvalidated licences despite the WTA saying they should.

Following a Freedom of Information request Ofcom revealed some statistics about current amateur radio licence holders
Among the information supplied by Ofcom were several licence charts included in a Power Point from a presentation given at the meeting with the RSGB on February 23, 2017.
These charts were:
• Live Licences by issue date (up until January 30,2017)
• How many years holders of Live Licences have held them
• Licence volume 2010-2017 showing numbers of Foundation, Intermediate, Full, Club and Reciprocal
The Live Licences by issue date chart shows two very prominent peaks around 1977 and 1981. The reason for these peaks could be because:
• The mid-1970's saw a surge of interest in 27 MHz AM/SSB CB radio. Radio amateurs were actively involved in the campaign for legalisation most notably James Bryant G4CLF who became President of the newly formed UK Citizens Band Association in 1976.
The licence volume chart shows that Ofcom had not revoked some 15,000 licences identified as Unvalidated back in May 2013. Figures released subsequently confirm that these licences, which have not been validated since 2007, remain Live Licences to this day.
In December 2015 Ofcom did Revoke a small test batch of some 529 unvalidated licences, this exercise told them how expensive the long revocation procedure (mandated by WTA 2006) was. They seem not to have repeated the exercise.