In 1960, the Home Secretary, Richard ‘Rab’ Butler, pressed for legislation, and the Cabinet appointed a committee. Butler oversaw the production of the Bill that became the Commonwealth Immigration Act of 1962. This controlled the immigration of all Commonwealth passport holders (except those who held UK passports). Prospective immigrants now needed to apply for a work voucher, graded according to the applicant's employment prospects.
Labour had fiercely opposed Commonwealth immigration controls but, once in office, was forced to reconsider. The experience of the 1964 elections, in which prominent opponents of immigration control lost seats, indicated the act had widespread support. In 1965, the government tightened administrative controls over immigration and reduced the number of vouchers available.
In 1967, Asians from Kenya and Uganda, fearing discrimination from their own national governments, began to arrive in Britain. They had retained their British citizenship following independence, and were therefore not subject to the act. The Conservative Enoch Powell and his associates campaigned for tighter controls. The Labour government responded with the Commonwealth Immigration Act of 1968. It extended control to those without a parent or grandparent who was born in or was a citizen of the UK.
The Conservative government announced the Immigration Act of 1971. The act replaced employment vouchers with work permits, allowing only temporary residence. 'Patrials' (those with close UK associations) were exempted from the act. It also tightened the immigration control administration and made some provision for assisting voluntary repatriation. In 1972, Idi Amin expelled large number of Asians from Uganda. Amid much controversy, the government permitted the immigration of 27,000 Asians through a specially constituted Uganda Resettlement Board.