Lord Goff of Chieveley

(delivering the judgment of the court): The second respondents ('the trustees') are the trustees of the estate of Syed Mohammed bin Armed Alsagoff. The trustees are the leaseholders, for the unexpired period of 999 years, commencing in 1890, of a substantial plot of land ('the land') fronting on Orchard Road in Singapore, the freeholder being the estate of Edwin Koek. On the land there are some two storey semi-permanent shophouses in a poor state of repair, which are occupied and are subject to the Control of Rent Act (Cap 58, 1985 Ed) Orchard Road is however an important commercial centre in Singapore, and the trustees regarded it as ripe for development. Accordingly on 15 June 1968 the trustees entered into an agreement in the nature of a building sub-lease with the appellant, Chew Ming Teck, who is a developer. Under the agreement, the trustees demised the land to the appellant, subject to the rights of the occupiers of the shophouses on the land, for a period of five years (with an option to the appellant to extend that period for a further four years), the appellant covenanting (1) to pay to the trustees an annual premium of $15,300.63; (2) to negotiate, settle and pay compensation (at his expense) to the occupiers of the shophouses, with a view to obtaining vacant possession of them; and (3) to pay all rates, taxes, etc on the land during the period of the lease. If the appellant successfully obtained vacant possession of the whole of the land, he was bound immediately to remove the existing buildings and works on the land, and to erect a multi-storey building of a certain specification upon it. Upon completion of the new building, the trustees were bound to grant to the appellant a lease for a term of 30 years upon terms set out in a schedule of the agreement, which provided, inter alia, that the appellant had the option to extend that term for two further periods of 30 years each. If the appellant failed to obtain the requisite planning and other consents to enable the development to take place, the appellant was entitled to determine the lease so granted to him.

On 18 July 1968, the appellant's architects submitted an application for planning approval for a 12-storey shopping/hotel building with a car park; and on 17 September 1968 he paid a security deposit of $106,000 to the Chief Building Supervisor. Following discussions with the planning authorities, a revised scheme was submitted on 7 July 1969 for an eight-storey shopping centre/office building with a car park. However on 21 October 1969 the appellant was informed that planning approval for the proposed development was refused on the ground that 'the site' is affected by a redevelopment scheme for the area. The appellant filed an appeal against this decision. In response, the Chief Building Surveyor submitted a written statement in which it was stated that the reason for refusal was based on the fact that the site was likely to be acquired for development by the Urban Redevelopment Department. The statement continued:

.. as far as planning/technical requirements are concerned, the proposed site is within the main shopping zone of the master plan, and therefore, there will be no particular objection to the development of the site for a shopping centre/office building. With regard to other technical requirements, like plot ratio, car parks, the applicant has taken these into account.

However on 24 June 1970, the government gazetted a declaration for the acquisition of the land. The appellant's appeal was heard on 6 October 1970 and dismissed on 28 October 1970. His deposit was returned. Objections made earlier by him to the acquisition of the land, in which he pointed out that his proposed development was similar to that now proposed by the Urban Redevelopment Department, had also been rejected.

Meanwhile, by letters dated 20 August and 8 September 1970, the Collector of Land Revenue ('the Collector'), who is the first respondent i