Its a vicious circle, the more people see public money isn't spend for their benefit, the more reluctant they will be paying it.
Also, the quite conservative midset of the British people has lead to self-centric thinking, i.e., "what do I get in return" instead of "what does the country get in return" , which is clear in every debate about public spending and taxes. While it is very clear what 15 years of austerity (not migrants!) has done to this country.