( 1 ) THIS petition has been Filed by the petitioners impugning the Demand Notices issued by Delhi Development Authority during the period 22/8/1991 to August 31,1991 and for issuance of a writ of mandamus directing the respondents to revise the cost of the tenements on the principles of "no Profit No Loss" basis as applicable to the tenements allotted to EWS (Economically weaker section) category. It is alleged in the writ petition that Delhi Development Authority, respondent No. 2 is responsible for constructing and for allotment of tenements to. various categories of registered persons including the EWS and according to the policy and practice of the respondents the cost of such flats are subsidised from the profit earned from disposal cost of houses allotted to middle and higher income groups of the Society and other sources. The registration scheme which concerns the petitioners was opened from 21/11/1985 to 30/12/1985 which period was extended subsequently. The details of the scheme as well as the averments made by the petitioners are incorporated in paragraphs 7 to 16 of the writ petition which may be reproduced as follows:

"7. That in clause I of the brochure it was stated by respondent No. 2 that the objective of the scheme was to provide built up tenements to the people residing in Slum areas, JJ Clusters, Unauthorised colonies Urban villages and other sub-standard areas on easy terms and conditions and keeping in view the affordability of the beneficiaries of the scheme and the overall objective of the scheme was to improve the quality of life of the people living in the sub-standard areas mentioned above. 8. That under the scheme 27693 persons were registered on payment of initial deposit of Rs. 3000. 00 per applicant. 9. That according to clause 5 (2) of the Brochure issued by respondent No. 2 the estimated cost of the tenements under the scheme was Fixed at Rs. 35000. 00 (approx) per unit. This price was,however, subject to revision in view of escalation in the cost of construction. 10. That believing in good faith in the representation made by respondent No. 2 that the cost of the tenements would be Rs. 35000. 00 approximately and further the policy of the respondent that Janta tenements for the EWS category are to be allotted on no profit no loss basis, the petitioners got themselves registered under the scheme on depositing the initial amount of Rs. 3000. 00. 11. That all the petitioners were issued registration certificate and deposit slips in respect of the amount deposited by them. That according to the norms prescribed by the CPWD and followed by respondent No. 2, the normal time taken for construction of group houses is 18 months. 12. That respondent No. 2 agreed to pay 7% interest on the initial deposit and adjust the principle and the interest against the cost of the tenements at the time of actual allotment of tenement. 13. That respondent No. 2 collected about Rs. 8. 5 crores from the initial deposits and kept them in time Fixed deposits and earning 10% interests (in the deposits. 14. That according to rule 6 (2) of the DDA (Disposal of developed naxul land) Rules, 1981 even residential plots for persons belonging to the lower-income group are to be allotted at pre-determined rates (no profit no loss basis) if they are living in Slum areas and other congested areas. 15. That the petitioners under the circumstances stated above did not make any effort to acquire any built up tenements of residential land in the Union Territory of Delhi from any other source and were eagerly waiting for allotment of tenement under the scheme of respondent No. 2. 16. That under the scheme of 1985 50% of the tenements were to be allotted on cash down and balance 50% on hire purchases basis. "

( 2 ) ON 2/11/1990 respondent No. 2 issued a Press notice inviting applications for allotment of 92 tenements at Inderlok on cash down basis only and since the petitioners needed the same urgently they applied for all