Jan, what we need in the UK is total transparency of tax returns, like Norway.
https://www.theguardian.com/money/blog/2016/apr/11/when-it-comes-to-tax-transparency-norway-leads-the-field
Most of the conflicts of the world are driven by perceptions of things being 'unfair'. From Afghanistan to Nigeria via Tunisia the dissent is driven by the perception that another tribe, religion, family, political party is ripping off the system, often aided and abetted by Western Governments and NGOs . (See Sarah Chayes excellent book Thieves of State
http://www.thievesofstate.com/).
It would appear from psychology experiments
https://en.wikipedia.org/wiki/Ultimatum_game that it's hard wired in to we humans that we'd rather we all have nothing than know that someone someone else is getting a lot more than us! (Which is why the idea that 'at least some of the foreign aid is getting to worthy causes, falls flat on its well meaning face).
With total transparency of tax returns those at the top ripping off the system would be shamed, as well as those at the 'bottom' who are living well beyond their supposed means being exposed.