( 1 ) THIS order will also govern the disposal of Misc. Petitions Nos. 552 and 553 of 1964 and Misc. Petitions Nos. 77, 219, 221, 224, 225 and 298 of 1965.

( 2 ) THESE are nine applications under Article 226 of the Constitution by colliers holding mining leases under the Government of Madhya Pradesh for the extraction of coal from collieries situated in the Chhindwara district of Madhya Pradesh State. All the petitioners challenge the vires of the, Madhya Pradesh Koyala Upkar (Manyata-karan) Adhiniyam, 1964 (Act No. 18 of 1964 [hereinafter referred to as the Validating Act] ), and seek a declaration that the said Act is constitutionally invalid, ultra vires and unenforceable and pray that a suitable direction be issued to the opponents forbearing them from giving effect to the Validating Act in any manner whatsoever. The petitioners in Misc. Petitions other than Misc. Petition No. 630 of 1964 and Misc. Petition No. 77 of 1965 also pray that the notices of demand issued to them after the coming into force of the Validating Act for payment of "coal cess" or "coal tax" at the rate of nine pies per ton for the period stated in the notices be also quashed by issue of writs