Nowhere was the political debate on the free movement of people in the EU more heated and divisive than in Brexit Britain, including on the British left. But in government at the turn of the century, the Labour Party had enthusiastically supported the free movement regime. Indeed, Prime Minister Tony Blair decided to immediately open UK labour markets to citizens of the new member states following the 2004 “big bang” enlargement, when he was not legally obliged to do so (Watt & Wintour 2015). For New Labour, this policy of opening had economic benefits and was consistent with a broader cosmopolitan Third Way ideology and its embrace of the EU as a single market (see Chapters 1 and 4). But the numbers of people that came to the UK from central and eastern Europe far exceeded the estimates (largely because they had assumed most member states, including Germany, would also open their labour markets in 2004) (Dustmann et al. 2003) and the issue grew in political salience, particularly after the 2007 economic crisis. As a result, long before the Brexit referendum in 2016, many in the Labour Party had come to regard Blair's 2004 decision as a spectacular policy failure: a critical juncture in the party's subsequent electoral decline. And with hindsight, given the breadth of opposition to the free movement regime by 2016, it is often regarded as a key moment in the country's drift towards Brexit (Constardine 2015; Geddes 2014; Evans & Mellon 2019).

Those associated with an old right Blue Labour and hard left anti-marketeer/ Lexiteer position discussed in Chapter 2 (position B, Figure 1.1), are among the most longstanding and vociferous critics of the free movement of persons regime. They opposed it in part for strategic reasons: as broad public opinion became critical of the regime it made little electoral sense to continue supporting the status quo. As we detail below, it was largely on this basis that many pro-European MPs in Labour and on the broader British left came to also express concerns about the party's positioning on the issue, both before and after the 2016 referendum.