The number of <a href="https://www.thenationalnews.com/tags/migrants/" target="_blank">migrants </a>living illegally in <a href="https://www.thenationalnews.com/news/europe/" target="_blank">Europe</a> has remained static for the past 15 years, contrary to public perception influenced by populist campaigners, according to a new study. According to the new estimates, between 2.6 and 3.2 million illegal migrants, known as "irregular" migrants, have been living in 12 countries in Europe. The numbers have actually fallen in countries which have experienced some of the most fervent anti-migration campaigns, such as the UK and Italy, while they have increased in Germany, where the far-right has gained a significant foothold. Irregular migrants make up around 1 per cent of the total population in those countries, and 8 to 12 per cent of all non-European-born migrants in EU countries and the UK. The data comes from new research by 18 institutions led by Oxford University’s Centre on Migration Policy and Society (Compas). They define an irregular migrant broadly as an individual with no legal right to be in a country, but the term does not include <a href="https://www.thenationalnews.com/tags/refugees/" target="_blank">refugees</a> whose asylum claims are being processed. Denis Kierans, senior researcher at Compas, explained why an accurate assessment of the number of irregular migrants is needed. “There has been a lot of public debate around the issue and this often tends to be hyperbolic or catastrophic without the evidence base to support it,” he told<i> The National. </i>“So what we see from the report is that the irregular migrant population hasn’t actually shifted much across the last 15 years. “But at various points over that time period you have a concern that’s being voiced by populations in different countries across Europe and by populations of different stripes that it’s actually on the rise. So sometimes we need that evidence to really keep the conversation grounded in reality.” Polling shows that irregular migration remains a concern for EU and UK citizens, with a survey carried out by BVA Xsight earlier this year showing 85 per cent of them believe Brussels needs to take more action to combat illegal immigration. Two thirds of UK citizens believe more should be done to exclude illegal immigrants, a poll for the National Centre for Social Research, also carried out this year, showed. <a href="https://www.thenationalnews.com/world/europe/2023/12/04/europe-seeking-silver-bullet-to-solve-illegal-migrant-crisis/" target="_blank">Anxiety about illegal immigration</a> propelled <a href="https://www.thenationalnews.com/world/europe/2023/11/23/dutch-election-geert-wilders/" target="_blank">Geert Wilders to victory</a> in last year’s general election in the Netherlands, and helped <a href="https://www.thenationalnews.com/tags/marine-le-pen/" target="_blank">Marine Le Pen’s </a>National Rally to become the<a href="https://www.thenationalnews.com/news/europe/2024/09/08/frances-le-pen-calls-for-referendum-to-break-political-deadlock/" target="_blank"> largest single party in the new French National Assembly</a>. But the Measuring Irregular Migration Project (MIrreM) researchers say numbers of illegal migrants have remained steady since 2008. Their study is built on another project from 2008 named CLANDESTINO, in which the number of irregular migrants in Europe was estimated as ranging from 1.8 million to 3.8 million. The new research, which is based on data from 2016 to 2023, increases the minimum estimate by 780,000 and decreases the maximum estimate by 460,000. That still leaves a “significant range” in which changes in the irregular migrant population since 2008 cannot be discerned, say the MIrreM researchers. “Overall, the irregular migrant population across the European countries we studied does not appear to have definitively changed since 2008,” said Mr Kierans. “However, there is significant variation at the national level, with some countries seeing increases, others decreases and still others witnessing no definitive change.” According to the study, the UK has the most irregular migrants, with the maximum figure estimated at 745,000, followed by Germany (700,000), Spain (469,000) and Italy (458,000). Compared to the 2008 estimates, the figures for the UK, Belgium, France and Italy have remained the same and have declined in Finland, Greece, Ireland, the Netherlands and Poland. In Austria, Germany and Spain, the number of irregular migrants has increased, the new estimates show. Mr Kierans explained that in some countries the numbers are shaped by the ability of irregular migrants to regularise their status by obtaining work or study permits, as well as others simply leaving to return home. He said that when it comes to the numbers for the UK, researchers had to use data from 2017, which predates the arrival of <a href="https://www.thenationalnews.com/news/europe/2024/10/05/minor-dies-and-asylum-seeker-flown-to-hospital-following-small-boat-incident-off-france/" target="_blank">migrants in small boats.</a> “We don't have data that shows us what has really happened in terms of the irregular migration so people don't understand the impact that these arrivals are having,” he said.