Altamas Kabir, J.

A point of considerable interest has been raised in these four writ applications which have been taken up for disposal together as they involve common questions of law and the facts are also similar in nature.

2. In all these four cases, the petitioners acquired the respective premises owned by them by purchase at different points of time and a common challenge has been thrown to the vires of clause (i) of sub-so (2) of s. 180 of the Calcutta Municipal Corporation Act, 1980, hereinafter referred to as "the 1980 Act".

3. In the case of Shree Mahamaya Mining and Industries Pvt. Ltd., the petitioner company appears to have purchased premises No. 28, Hindustan Road, Calcutta, on 21st September, 1991, at a consideration of Rs. 58, 00,000/-. According to the petitioners, at the time of purchase of the said property there was an existing structure with foundation and construction upto plinth level with R.C.C. pillars upto the ground floor roof level. At the time of purchase, the existing Annual Valuation of the premises was Rs. 7,030/-, which was in effect from the third quarter of 1983-84.

4. On 11th August, 1983, the petitioners were served with a notice by the Ca