Law for revenue is necessarily the command of sovereign, may by arbitrary,may not always be rational or standard. Revenue laws keep changing as per whim, necessity, wealth available and required and as per the level of education available to state and its subjects.
Revenue laws are enforced through command of sovereign .
This branch should always be watched jealously by courts of justice and very strictly whenever it comes to courts of law.
So long the institution of state and governance through state is acquiesced , accepted and ratified we will have to bear the stress of tax laws . Only a vigilant court of law can keep tax laws within bearable range otherwise tax laws will be gateway to  oppression, suppression and corruption. A vigilant judicial system can only ensure a proper legal check and balance on state greed.
Liberty is also frequently attacked through state made tax-law and these are known to be in gross misuse for political purposes also. Human rights are also abrogated, subjugated, violated through the tax- law mechanism , that too surreptitiously .
A court of law must ensure that each and every move under tax law has the strict  sanction  of law in substance, procedure and mode.
Tax laws rob the people lawfully and hence only law and nothing else be permitted to do so.