How to REALLY raise the tax income
Decrease collection costs. Simplify the systems whilst removing most of the exemptions which have been rolled in to appease various consituencies.
Seriously. It works. Overall gross tax revenue goes down, but overall NET tax revenue goes up.
If govt can net more money with less tax then there's more in the economy to spend in the first place.
There are _far_ too many people working at HMRC and other boondoggles such as DVLA and every time a new IT project is rolled out it's used as an excuse to employ MORE people, instead of a way of getting rid of them.
Civil service "employment" is frequently used as a way of hiding true unemployment statistics. There's no way areas like the Northeast of England should have 60% of its economy dependent on people working for the government for the same reason there's no area should have those kinds of numbers dependent on any other single employer.