[baddox]

Yes, but the precise amount of taxes you should pay is not some moral principle. If the current tax laws were the “correct” amount, then the government passed a tax cut, are you morally obligated to keep paying the higher amount?

[r3bl]

If those tax cuts were given specifically to you (as is the European Commission's conclusion[0]), then yes. It's immoral to pay less.

[0] http://europa.eu/rapid/press-release_IP-16-2923_en.htm