The Supreme Court today declared the National Tax Tribunal Act as unconstitutional under which a tribunal was set up to decide tax-related cases by taking away jurisdiction of high courts in such matters.

A five-judge constitution bench headed by Chief Justice R M Lodha said, the Act passed by Parliament in 2005 is unconstitutional as the National Tax Tribunal encroaches upon the power of higher judiciary, which can only decide issues involving substantial laws and not a tribunal.

The apex court passed the order on a batch of petitions challenging the constitutional validity of the Tribunal.