local businesses over the long-term viability of further real estate investment. By the time negotiations began over the future of the colony in the early 1980s, China had since become communist. Local residents were apprehensive about the prospect of being handed over to Chinese rule and overwhelmingly preferred that Hong Kong remain a British territory; contemporary opinion polls show that 85 per cent of residents favoured this option. The British government attempted to negotiate an extension of its administration of Hong Kong past 1997, but pivoted towards ensuring the city's stability when it became clear that the Chinese authorities would not allow this. The two governments agreed on the Sino-British Joint Declaration in 1984. The United Kingdom would transfer the entire territory of Hong Kong at the conclusion of the New Territories lease in 1997 to the People's Republic of China, which promised to guarantee the continuation of the region's existing economic and political systems for 50 years after the handover. Hong Kong would become a special administrative region governed under Chinese sovereignty with a high level of autonomy in local affairs and its residents were to retain civil liberties such as freedom of speech, assembly, and religion after the transfer. Nationality arrangements for residents Before 1983, all citizens of the British Empire, including Hongkongers, held a common nationality. Citizens of the United Kingdom and Colonies (CUKCs) had the unrestricted right to enter and live in the UK, although non-white immigration was systemically discouraged. Immigration from the colonies and other Commonwealth countries was gradually restricted by Parliament from 1962 to 1971 amid decolonisation, when British subjects originating from outside of the British Islands first had immigration controls imposed on them when entering the UK. After passage of the British Nationality Act 1981, CUKCs were reclassified into different nationality groups based on their ancestry and birthplace, and the vast majority of British subjects in Hong Kong became British Dependent Territories citizens (BDTCs) with the right of abode only in Hong Kong. Only those reclassified as British citizens held an automatic right to live in the United Kingdom. The British government issued a memorandum attached to the Joint Declaration that concerned transitional arrangements for the nationality of residents, which included a stipulation that a new nationality would be created for Hongkongers that did not confer right of abode in the United Kingdom. The Hong Kong Act 1985 created the British National (Overseas)