Office for National Statistics migration estimates published in November 2021 suggest that the number of EU nationals leaving the UK exceeded the number arriving by around 94,000, compared to net inward migration from the EU to the UK of 32,000 in 2019. Some commentators suggested that these figures underestimate the extent of emigration of EU nationals from the UK. Immigrants from the European Union One of the Four Freedoms of the European Union, of which the United Kingdom is a former member, is the right to the free movement of workers as codified in the Directive 2004/38/EC and the EEA Regulations (UK). With the expansion of the EU on 1 May 2004, the UK has accepted immigrants from Central and Eastern Europe, Malta and Cyprus, although the substantial Maltese and Greek-Cypriots and Turkish-Cypriot communities were established earlier through their Commonwealth connection. There are restrictions on the benefits that members of eight of these accession countries ('A8' nationals) can claim, which are covered by the Worker Registration Scheme. Many other European Union member states exercised their right to temporary immigration control (which ended in 2011) over entrants from these accession states, but some subsequently removed these restrictions ahead of the 2011 deadline. The United Kingdom uses statistics to predict migration that are produced primarily from the International Passenger Survey conducted by the Office for National Statistics (ONS). The survey's primary mission is to help government's understand the effects of tourism and travel on their economy. Two parliamentary committees criticized the survey and found it to lack credibility. The actual net migration in 2015-16 from EU states to the United Kingdom, 29,000, was 16% higher than the ONS expected. Research conducted by the Migration Policy Institute for the Equality and Human Rights Commission suggests that, between May 2004 and September 2009, 1.5 million workers migrated from the new EU member states to the UK, but that many have returned home, with the result that the number of nationals of the new member states in the UK increased by some 700,000 over the same period. Migration from Poland in particular has become temporary and circular in nature. In 2009, for the first time since the enlargement, more nationals of the eight Central and Eastern European states that joined the EU in 2004 left the UK than arrived. Research commissioned by the Regeneration and Economic Development Analysis Expert Panel suggested migrant workers leaving the