( 1 ) THE petitioners in all these petitions are manufacturers of Vanaspati (hydrogenated vegetable oil) and/or Soap. Till 1-3-1987 the petitioners were manufacturing Vanaspati/soap from conventional oils because they give high process yield and are cost effective compared to nonconventional minor oils like Rice-Bran oil, Mahuva oil, Water Melon Seed oil, Solvent Kardi oil, etc.

( 2 ) IN order to encourage use of minor oils, the Central Government introduced in 1986-87 a system of rebate in excise duties for Vanaspati and soap linked to larger use of such minor oils. It inserted on 1-3-1987 Sec. AAA containing Rules 57k to 57p in Chapter V of the Central Excise Rules. On that very day the Government also issued under Rule 57k Notification no. 27 of 1987 and Notification No. 40 of 1987 specifying the final products, minor vegetable oils and rates at which credit was to be given for use of such minor oils in manufacture of Vanaspati and Soap, respectively. Notification no. 40 of 1987 was superseded by Notification No. 192 of 1987-CE and the later notification was subsequently amended by Notification No. 17 of 1988-CE dated 1-3-1988.

( 3 ) IT is the case of the petitioners