( 1 ) THIS Writ Petition challenges the notice dated 12,2. 1973 issued by Land and Development Office to the petitioner terminating the perpetual lease in their favour for violation of clause 6 of the prepetual lease. Before terminating the lease a notice was given to the petitioners informing that that on inspection of the premises on 4. 11. 1970 it was observed by the Inspecting Officer that an area measuring about 2843 sq, ft. in the main building at the ground floor of 48, Hanuman Road, New Delhi, (the leased property) was being used as Doctor s clinic (Ex-Ray Electro-Medical and Skin Clinic), The said notice called upon the petitioners to remove the breach within thirty days. On the failure of the petitioners to comply with the said notice, order terminating the perpetual lease was passed against the petitioners. It may be noted at this stage that the said Ex-Ray and Electro-Medical and Skin Clinic was being run by Dr. Ved Prakash who was the tenant of the petitioners. On 2. 4 1973 the petitioners filed the suit against Dr. Ved Prakash and others for recovery of possession under clause (k) of the proviso to section 14 of the Delhi Rent Control Act alleging that D