British Nationality Act 1981

The British Nationality Act 1981, Chapter 61, is an Act of the Parliament of the United Kingdom concerning British nationality since 1 January 1983.

In the mid-1970s the British Government decided to update the nationality code, which had been significantly amended since the British Nationality Act 1948 came into force on 1 January 1949. In 1977, a Green Paper was produced by the Labour government outlining options for reform of the nationality code. This was followed in 1980 by a White Paper by the Conservative government that closely followed the Labour proposals. William Whitelaw, the Home Secretary under Prime Minister Margaret Thatcher, was the chief author. The British Nationality Act 1981 received Royal Assent on 30 October 1981 and came into force on 1 January 1983. Both major parties were in agreement on the new law.

Subsequently, the British Nationality Act has been significantly amended, including:

The Act had a number of purposes.

The Act reclassified Citizenship of the United Kingdom and Colonies (CUKC) into three categories:

Since 1962, with the passage of the Commonwealth Immigrants Act 1962, not all CUKCs had the Right of Abode in the United Kingdom. The Act sought to restore once again the link between citizenship and right of abode by providing that British citizenship—held by those with a close connection with either the United Kingdom or with the Crown Dependencies (that is to say, the Isle of Man and the Channel Islands), or both—would automatically carry a right of abode in the UK. The other categories of British nationality would not hold such status based on nationality, although in some cases would do so under the immigration laws.

Whilst in opposition in 1977, the Conservative Party asked Edward Gardner to chair a study group to provide advice on changes to the nationality laws. The resultant Green paper, "Who Do We Think We Are?", was published in 1980 and its threefold definition of nationality formed the basis for the Government's legislation. Originally the paper proposed just two categories of British nationality, British citizenship and British Overseas citizenship. However, the British Dependent Territory governments successfully lobbied for an additional category of nationality, which would cater for those with close connections to any of the British territories.

...
Wikipedia