Why should they want to do this ?
We have had someone saying that in the last 50 years there have been no prosecutions of anyone solely for having a slightly over power(13 FPE was stated) air rifle.
If there have been no prosecutions it seems strange that there should be any concern. What do they base this concern on.
There are two section in law where the Secretary of State for the Home Office can alter the legislation without recourse to Parliament. There would be severe consequences of them doing this and it couldn't be done lightly.
The Government has said they do not want to ban airguns as the compensation would cost too much. They admit their mistake on not paying for the Brococks (around 80,000 missing). Licencing would be a difficult course of action and would result in many thousands of airguns going missing.
Lowering the power limit would mean millions of overpowered guns immediately it came into force and the probable loss of hunting.
Easy to change the law but not easy to avoid the problems of doing so.