French president Macron has recently caused controversy with his contrast of extra-EU legal immigration and intra-EU illegal movements of EU/EUAA people:
Last week, the right-wing French magazine Valeurs Actuelles published an interview with Macron who said he favored legal quota-based migration to illegal workers, contrasting Guinean or Ivorian migrants who work legally to "clandestine gangs of Bulgarians and Ukrainians."
(Macron also recently opposed further EU enlargement in the Balkans.)
Are illegal movements of EU citizens in the EU a significant problem? E.g. is there a significant black market for Eastern EU labor in the West, for instance in prostitution, undeclared day labour, and similar? Are there any estimates for the magnitude of these phenomena? Likewise, are there similar estimates for the EU-associated countries like the Ukraine?
N.B. there's some controversy how to even translate what Macron said in French
In French: «Je préfère avoir des gens qui viennent de Guinée ou de Côte-d’Ivoire légaux, qui sont là et qui font ce travail, que des filières bulgares ou ukrainiennes clandestines.»
Macron’s words about “clandestine Bulgaria or Ukrainian networks” with respect to illegal immigration remain somewhat unclear given that as an EU member state Bulgaria’s citizens are entitled to live and work in France. Ukraine has not been recognized as an official EU candidate country but its citizens were granted visa-free travel to the EU back in 2017.
In the previous sentence Macron used a phrase that's probably even harder to translate "travail détaché dissimulé" in a parallel contrast, so he seems to attach this latter form of "dissimulated" work with Bulgarian and Ukrainian networks/gangs:
La brouille a débuté après un entretien publié dans Valeurs actuelles, au cours duquel Emmanuel Macron a estimé - au sujet de la politique migratoire de la France - "préférer avoir de la migration légale, enregistrée, sous quotas, pendant X années, plutôt que du travail détaché dissimulé". Et d'appuyer : "Je préfère avoir des gens qui viennent de Guinée ou de Côte d'Ivoire légaux qui sont là et qui font ce travail (pour des secteurs comme le BTP et la restauration ayant besoin de main-d'œuvre étrangère) que des filières bulgares ou ukrainiennes clandestines".
Note that "travail dissimulé" is a legal term in France roughly translated as "dissimulated [hidden] work", basically undeclared/illegal work. The latter document also says it's most prevalent in entertainment, farming, construction, transportation, and hospitality business[es] in France. However it's not clear from that document if Eastern EU (or EUAA) workers are overrepresented in this "dissimulated work".