Uganda by Idi Amin in 1972. There was also an influx of refugees from Hungary, following the crushing of the 1956 Hungarian revolution, numbering 20,990 people. Until the Commonwealth Immigrants Act 1962, all Commonwealth citizens could enter and stay in the UK without any restriction. The Act made Citizens of the United Kingdom and Colonies (CUKCs), whose passports were not directly issued by the UK Government (i.e., passports issued by the Governor of a colony or by the Commander of a British protectorate), subject to immigration control. Enoch Powell gave the famous "Rivers of Blood" speech on 20 April 1968 in which he warned his audience of what he believed would be the consequences of continued unchecked immigration from the Commonwealth to Britain. Conservative Party leader Edward Heath fired Powell from his Shadow Cabinet the day after the speech, and he never held another senior political post. Powell received 110,000 letters only 2,300 disapproving. Three days after the speech, on 23 April, as the Race Relations Bill was being debated in the House of Commons, around 2,000 dockers walked off the job to march on Westminster protesting against Powell's dismissal, and the next day 400 meat porters from Smithfield market handed in a 92-page petition in support of Powell. At that time, 43% of junior doctors working in NHS hospitals, and some 30% of student nurses, were immigrants, without which the health service would needed to have been curtailed. By 1972, only holders of work permits, or people with parents or grandparents born in the UK could gain entry – significantly reducing primary immigration from Commonwealth countries. Immigration as influenced by the EU (1983–2022) The British Nationality Act 1981, which was enacted in 1983, distinguishes between British citizens and British Overseas Territories citizens. It also made a distinction between nationality by descent and nationality other than by descent. Citizens by descent cannot automatically pass on British nationality to a child born outside the United Kingdom or its Overseas Territories (though in some situations the child can be registered as a citizen). Immigration officers have to be satisfied with a person's nationality and identity and entry can be refused if they are not satisfied. During the 1980s and 1990s, the civil war in Somalia led to a large number of Somali immigrants, comprising the majority of the current Somali population in the UK. In the late-1980s, most of these early migrants