Bulgarians and Romanians can be expelled through a so-called APRF, or 'prefectoral decision to be conducted at the border', on the basis of threats to public order or infringements of labour legislation.
If the citizens concerned fail to produce a residence permit authorising them to work, they are subjected to such steps, Nabli explains, adding that the situation will remain unchanged until 2014, when nationals of the two EU countries will not be tied down by work restrictions.
Another measure, called OQTF, or 'Obligation to leave French territory', can be taken in the event that the residence permit cannot be maintained or in the event of unemployment, when the individuals concerned do not have enough resources to meet their needs and are without medical coverage.
Regarding the Roma expulsions, Nabli says that they appear to contradict the Charter of Fundamental Rights of the European Union, which entered into force together with the Lisbon Treaty. He notes that the principle of non-discrimination protects the minorities' rights and prohibits collective expulsions.
Nabli argues that "freedom of movement has no price" and consequently criticises the 300 euros of "assistance for departure" that the French authorities offer Roma (plus 100 euros per child) for receiving their signature on agreeing to leave French territory.
If the European Commission finds the French authorities to be infringing EU law, it could start an infringement procedure against France. Accordingly, the Commission would have to state France's faults and what measures should be taken to solve the problem.
Any breach must be declared by the European Court of Justice and can lead to a condemnation, requesting France to abide by its obligation, or else imposing fines. This type of judgment has a strong political effect, as the image and the credibility of the condemned state suffer, the French expert concludes.
To read the full text of the interview in French, please click here.