EU enlargement would add about 65mn people to a bloc running out of workers, and much of the migration voters fear has already happened, a report from the Brussels-based Centre for European Policy Studies (CEPS) argues.

The policy brief published on September 25 and written by Tinatin Akhvlediani, head of its EU enlargement programme, argues that labour mobility from the next wave of accessions should be treated as an economic dividend rather than a threat. By 2050 the working-age population is projected to shrink in 22 of the EU's 27 member states, and if labour force participation stays where it is, the bloc will have 42.8mn fewer workers by 2070.

The countries of Central and Southeast Europe that sent workers west after 2004 now import them, from Ukraine and now also from Asia, and several of their governments are tightening the rules even as employers warn they cannot fill vacancies. Brussels is also drafting plans to give candidates phased access to the single market before they join.

"The central question isn't whether labour will move after enlargement, but whether that movement is managed in a way that supports growth, protects workers and limits adjustment pressures in both origin and destination countries," Akhvlediani writes.

Fears that did not come true

The 2025 Special Eurobarometer on enlargement, the public opinion CEPS is trying to move, found that 56% of Europeans back further expansion, but 40% named uncontrolled migration as a concern, the most cited worry, and 27% feared for jobs or wages.

The same fears preceded the 2004 "big bang", when 10 Central and Eastern European countries brought more than 74mn people into the bloc, followed by about 33mn more from Bulgaria, Romania and Croatia. Forecasts at the time were for net migration of 300,000-400,000 a year from the new members. Actual annual flows from the eight CEE accession states were closer to 200,000-250,000, and by 2009 around 1.8% of their combined population had moved to the older member states, adding only about 0.4% to the latter's population.

Studies cited by CEPS put the rise in unemployment in the old member states at 0.06 percentage points in the short term and 0.02 points in the long term, and the fall in average wages at about 0.1%, an effect that faded as investment caught up. Post-enlargement mobility lifted the enlarged EU's GDP by around 0.11% in the short run and 0.2% in the long run, equivalent to roughly €24bn.

Where workers went depended on who let them in. Germany and Austria had taken around 60% of migrants from the accession countries before 2004 but kept transitional restrictions afterwards, and were overtaken by the UK and Ireland, which opened their labour markets at once. By 2007 workers from the new members made up about 5% of Ireland's working-age population. The flows also reversed: UK net migration from the 2004 entrants fell from 87,000 in 2007 to 16,000 in 2009.

In the UK, 44.6% of post-2004 migrants from the new member states worked in elementary occupations, despite education levels broadly comparable with those of local workers, and the risk of exploitation was concentrated in insecure, weakly regulated jobs.

From labour exporters to labour importers

Poland is CEPS' main example of how the cycle turns. Emigration rose after accession, but growth pushed unemployment to among the lowest rates in the EU, and Warsaw then opened its labour market to workers from Ukraine and Belarus. The country had 1.15mn foreign workers at the end of March, up 8% y/y, of whom 783,900, or 68%, were Ukrainian, according to the statistics office GUS.

"If such a situation were to happen - when all Ukrainians agreed and did not go to work - the Polish economy would come to a standstill," Deputy Interior Minister Maciej Duszczyk warned in August. Poland is already losing some of that labour further west: Ukrainian refugees there earn about €973 a month against €1,227 for Polish workers, and some are moving on to Germany and the Netherlands.

Between 2005 and 2025 Latvia's population fell by 17%, Bulgaria's by 16%, Lithuania's by 14%, Romania's by 11% and Croatia's by 10%, Eurostat data show, part of a global demographic crisis that has left the region with too few young workers to replace those retiring.

Governments have answered with tighter controls as often as with open doors. Hungary's new Tisza government moved in May to freeze work permits for non-EU nationals from June 1 and review the rules, before settling on tighter conditions rather than an outright ban. Poultry producer Master Good said its planned HUF350bn (€1bn) expansion would be unfeasible under the new regime. Croatia, which issued 136,194 residence and work permits in the first nine months of 2025, has moved to require a basic language test for most foreign workers renewing their permits. Lithuania used up its entire 2026 quota of 24,706 foreign workers by September 7 and is closing its migration centres in Kazakhstan, Kyrgyzstan and Uzbekistan on November 1.

Workers from the candidate countries would arrive with EU rights rather than as third-country nationals. CEPS says workers from candidate countries are younger and more educated on average, and that, if employed, they can contribute through taxes and social security payments.

Much of the move has already happened

The nine countries in the process - Albania, Bosnia & Herzegovina, Montenegro, North Macedonia, Serbia, the potential candidate Kosovo, Ukraine, Moldova and Georgia - have a combined population of about 64.5mn, well short of the roughly 107mn brought in since 2004. Turkey is left out of the calculation because its accession talks have been frozen since 2018. Nor are the nine likely to join at once.

A large share of their emigration has already taken place. Eurostat figures compiled by CEPS put about 17% of Kosovo's population and 14% of Albania's in the EU in 2025, along with 10.9% of North Macedonia's, 9.6% of Bosnia's, 6% of Serbia's, 4.9% of Montenegro's, 4.7% of Moldova's and 2.1% of Georgia's. Albania's population fell 1.2% in 2025 alone, with net emigration of 28,531 people.

Ukraine is the clearest case of labour market integration running ahead of accession. Some 4.41mn people who fled the war hold temporary protection in the EU, led by Germany with 1.29mn, Poland with 961,170 and the Czech Republic with 390,810. That protection has been extended to March 2028, and CEPS expects those who have found work to stay in their host countries even if it lapses, a view shared by the Dutch Clingendael Institute, which concluded in May that millions are likely to remain for years.

Convergence beats restrictions

The candidates' GDP per capita in purchasing power terms is on average less than half the EU level, and Ukraine has overtaken Moldova as Europe's poorest country. CEPS argues that the gap is comparable to the one the CEE states brought in 2004, and that what decides migration is whether incomes converge, not how wide the gap is on accession day. Long delays to accession can themselves push people out if workers see better chances abroad and little prospect of catching up at home, the brief warns.

CEPS' four recommendations follow from that. Pre-accession aid should put productivity growth and job creation first. The EU should promote circular and return migration, recognise qualifications faster and link public employment services across current and future members. Transitional limits on free movement should target sectors or regions under demonstrable strain and be coordinated at EU level, since purely national restrictions tend to divert workers to other member states or into false self-employment rather than stop them, the brief says. And cohesion money should flow to the cities and regions that receive the most newcomers.

Montenegro had provisionally closed 18 of the 33 negotiating chapters it has opened by mid-July, including chapter 2 on the free movement of workers in June, while Ukraine opened its first negotiating cluster the same month and the European Commission is drafting a roadmap for its EU accession bid that covers gradual integration into the free movement of people.

"Seen in this light, labour mobility should not be treated primarily as a cost of enlargement. Properly managed, it can become one of its economic dividends," CEPS concludes.