K. A. Puj J. - Since a common issue is involved in all these petitions and since they are heard together, the same are being disposed of by this common judgment and order.

The petitioners have initially filed these petitions praying for quashing and setting aside the circular dated September 2, 2005 issued by the Commissioner of Sales Tax, Ahmedabad. The petitioners have alternatively prayed for declaration that the circular dated September 2, 2005 revoking and/or cancelling the circular dated February 19, 2001 cannot have any retrospective effect. This court vide its common judgment ([2009] 22 VST 569) dated 23-25 and 30, April 2007 partly allowed the petitions and clarified that in respect of the period post - September 2, 2005, the Sales Tax Department would be at liberty to issue notices to the petitioners under section 50 of the Act on the ground of alleged breach of condition of exemption by the petitioners. It was further clarified that the petitioners in response thereto would be at Liberty to lead evidence and make submissions before the authorities to establish that the goods used by them fall within the expression "used by him as raw material, processing materia