T.S. THAKUR, J.

These petitions, seeking a writ of certiorari, the petitioners have called in question the constitutional validity of notification dated March 31, 2000, issued by the Lt. Governor of NCT of Delhi, under section 71 of the Delhi Sales Tax Act, 1975 (for short, "the Act") to the extent it has introduced gutka as one of the items in the First Schedule to the Act retrospectively with effect from April 1, 2000. The petitioners have also assailed the correctness of reassessment orders made by the assessing authority for the periods 2000-2001 and 2001-2002 and the demands raised on the basis thereof.

The petitioners are engaged in the manufacture of gutka, pan masala and chewing tobacco and are registered as dealers under the State and Central sales tax enactments. Assessments for the years 2000-2001 and 2001-2002 were reopened in terms of notices dated August 16, 2005, culminating in reassessment orders under the State Act as also the Central Act and raising of consequent demands for payment of taxes under the two enactments. Aggrieved, the petitioners have assailed the said orders of reassessment apart from challenging the vires of notification dated March 31, 20