I am sorry Bri - that reads like the last Conservative/Labour/LibDem manifesto.
Gas Safe does not protect the public - the daughter of the publisher of Future Publishing was killed by carbon monoxide poisoning - a plumber is currently in court on this case. Part P was a licence to provide qualifications to people who have not completed a full electrical training course. We already have the posts here about the CSCS fiasco.
I appreciate your desire to root out the people who complete sub standard work - but licensing will not do that. Its like comparing the theory of Karl Marx with the reality of Stalins Russia - noble theories that get corrupted in practice.
Steer well clear of any licensing scheme introduced by this or any other Government - and please dont encourage them.