The European Commission has told France that it faces action over its expulsion of Roma (Gypsy) migrants if it fails to adopt EU rules on freedom of movement by 15 October.
France welcomed the fact that the EU was not accusing it of discrimination.
But Justice Commissioner Viviane Reding said France had not respected a 2004 EU directive on freedom of movement.
The expulsions of thousands of Roma from France has led to a serious row between Brussels and Paris.
Recently Ms Reding compared France's action to events during World War II.
The accusation drew a sharp rebuke from President Nicolas Sarkozy.
Ms Reding says France has failed to transpose into law a 2004 EU directive on freedom of movement, which sets out procedures for deporting migrants deemed to be staying illegally.
The BBC reports that Roma sent home to Romania and Bulgaria are EU citizens, so they have the right to move to another EU country.
But host countries can deport people considered to be a public security risk or a burden on the welfare system.
Mr Sarkozy says illegal Roma camps threaten to become shanty towns.
He launched a crackdown in late July, calling the camps breeding grounds for people trafficking, prostitution and child exploitation.
More than 1000 Roma have been deported since Mr Sarkozy announced that the camps would be torn down.