The introduction of a dichotomy in patent law between pre-grant and post-grant opposition necessitates adherence to legislative intent, despite procedural delays in enactment.

1Leave granted.

2. For the sake of convenience we refer to the facts mentioned in Civil Appeal No. 5184 of 2008 [arising out of SLP (C) No. 15729 of 2008] filed by J. Mitra & Co. (P) Ltd.

3. This matter is a classic illustration of the confusion which has emerged on account of the postponement of in part commencement of the Patents (Amendment) Act, 2005 .

4. Quite often the commencement of an Act is postponed to some specified future date or to such date as the appropriate Government may, by notification in the Official Gazette, appoint. Provision is also at times made for appointment of different dates for coming into force of different parts of the same Act. This is what has exactly happened in this case resulting in utter confusion with regard to pending FAO No. 293 of 2006 filed by Respondent 3 in the High Court under S.116 of the Patents Act, 1970 as amended by the Patents (Amendment) Act, 1999 w.e.f. 26-3-1999.

5. Span Diagnostics Limited, Respondent 3 herein, is a public limited company established in 1972 to indigenously develop and manufacture a comprehensive range of readymade diagnostic reagents used by clinical pathology laboratories.

6. On 14-6-2000 J. Mitra & Co. (P) Ltd., appellant herein, filed its application for grant of patent. After scrutiny, the said application stood notified by the Patent Office on 20-11-2004. Thus, proceedings commenced before the Controller of Patents in the year 2000 when the appellant herein sought a patent of their device which was opposed by Respondent 3 in the year 2000. By then, the Patents (Amendment) Act, 1999 had amended the Patents Act, 1970 w.e.f. 26-3-1999. S.25 of the as amended by the Patents (Amendment) Act, 1999 dealt with opposition to a patent vide S.25. At that time appeals against decisions made by the Controller pertaining to "pre grant oppositions" under S.25 were maintainable before the High Court under S.116(2) of the .

7. We quote hereinbelow S.25 and 116 as they stood in the year 2000 under the Patents (Amendment) Act, 1999 which read as under:
"25. Opposition to grant of patent.-(1) At any time within four months from the date of advertisement of the acceptance of a complete specification under this Act (or within such further period not exceeding one month in the aggregate as the Controller may allow on application made to him in the prescribed manner before the expiry of the four months aforesaid) any person interested may give notice to the Controller of opposition to the grant of the patent on any of the following grounds, namely
(a) that the applicant for the patent or the person under or through whom he claims, wrongfully obtained the invention or any part thereof from him or from a person under or through whom he claims;
(b) that the invention so far as claimed in any claim of the complete specification has been published before the priority date of the claim-
(i) in any specification filed in pursuance of an application for a patent made in India on or after the 1st day of January, 1912; or (ii) in India or elsewhere, in any other document: Provided that the ground specified in sub clause (ii) shall not be available where such publication does not constitute an anticipation of the invention by virtue of sub-section (2) or sub-section (3) of S.29;
(c) that the invention so far as claimed in any claim of the complete specification is claimed in a claim of a complete specification published on or after the priority date of the applicant's claim and filed in pursuance