Is Fringe benifit tax valid?

Dear Mr Assumi:

The levy of Fringe Benefit Tax is constitutionally valid as the act is passed by legislation of the parliament. The relevant charging section  is reproduced hereunder:

Charge of fringe benefit tax.

115WA. (1) In addition to the income-tax charged under this Act, there shall be charged for every assessment year commencing on or after the 1st day of April, 2006, additional income-tax (in this Act referred to as fringe benefit tax) in respect of the fringe benefits provided or deemed to have been provided by an employer to his employees during the previous year at the rate of thirty per cent on the value of such fringe benefits.

(2) Notwithstanding that no income-tax is payable by an employer on his total income computed in accordance with the provisions of this Act, the tax on fringe benefits shall be payable by such employer

But income tax is a tax on income not on expenditure;  and fringe benifit tax is a tax on expenditure and not on income and as such there is anamoly?

for certain purposes Fringe benefits are taken as income, hence, taxable.