Why?Not a hope of that happening. Any government would find themselves in court if they tried that.
It was ofcom that changed the rules to allow this ridiculous situation whereby the "local" radio frequencies don't have to broadcast any local output.
Presumably this was at the behest of one of the owning groups pointing out they could improve profits if they only had the same 2 presenters on the breakfast show in Lincoln, Exeter and Dundee.
Are the licences to broadcast still for fixed periods of time? Then if so, there is absolutely no reason why, in future, there can be increased levels of local output specified.