Uday Sinha, J.

1. These four writ petitions under Articles 226 and 227 of the Constitution raise common questions of law. They have, therefore, been heard together and are being disposed of by this common judgment.

2. The questions agitated at the Bar are pure questions of law. They relate to the ambit/vires of notifications (annexures 1, 1/A and 1/B, all dated 7th November, 1984). As a follow up of those annexures, the Bihar Government in the Finance (Commercial Taxes) Department issued notice (annexure 2) whereby all Government departments, Board and Organisations were directed to deduct 4 per cent of the bills of all contractors engaged in works contract. In essence, the petitioners have prayed for quashing of annexures 1 series and annexure 2. Since the questions agitated are pure questions of law, it is not necessary to advert to the additional prayer of the petitioners in the different writ petitions for quashing the deductions in the bills of the petitioners.

3. The petitioners are contractors registered with various departments of Government of Bihar for executing works contracts. In terms of the contracts, materials like bitumen, "cement, steel rods, etc., are/were