The political science literature is extremely limited in explaining the influences on UK migration policy making. An important exception is the work of Hansen (2000). Hansen draws on the theory of ‘path dependency’, where policy changes must be seen in the context of previous policy decisions, to explain change over the last half century. He explains policy development from the 1948 British Nationality Act, which drew the boundaries of entry and citizenship widely and set a crucial direction (or ‘path’) that subsequent policy grappled with (in trying to rein in the boundaries). After 1962, he sees the source of restrictionism in British institutions and in particular in two aspects of the Westminster model: a weak legislature and the lack of a Bill of Rights. Britain's government, free from legislative and judicial checks, thus had a freer hand and imposed greater restrictionism from the 1960s onwards (Hansen, 2000, pp 240–3). However, given that Hansen (2000) is explaining a situation of ‘zero-migration’, his explanation for immigration policy change under Labour is unconvincing.

Part Two aimed to provide a fuller account of the influences, inputs and transformational processes that have operated upon the construction of UK migration policy. Influences have included the processes and perceptions of globalisation; the UK legal framework; the impact of the European Union and its powers; the attitudes of the public towards immigrants; the role of the media, particularly the tabloid press; the array of interest groups, government departments, NGOs and think tanks; senior Labour politicians, political parties, and the impact of major events; as well as officials themselves. In order to make sense of these numerous influences, the conclusions presented below are simplified into three tiers: macro, meso and micro. This does not seek to privilege one over another, but may contribute to analytical clarity (Hudson and Lowe, 2004).

On a macro level, three major influences emerge. The first is the series of processes that can be loosely described as ‘globalisation’. Prior to 1997, policy did not grapple with globalisation and the economic trends it serves to magnify and expose. Policy development after 1997 has taken account of global labour flows, adapting to the major numerical increases in passenger numbers and immigrant flows resulting form globalisation. Furthermore, globalisation has an ideological dimension in helping set the ‘rules of the game’.