The government's move comes three days after a French parliament report called for a ban on the burqa and niqab, saying Muslim women who fully cover their heads and faces pose an "unacceptable" challenge to French values.
Fillon wrote to the State Council, the country's highest administrative court, asking it to "study the legal solutions enabling us to reach a ban on wearing the full veil, which I want to be as wide and effective as possible."
He asked the court to "help the government find a legal answer to the concerns expressed by parliament's representatives and to rapidly submit a bill on the subject to parliament."
The State Council is to submit its findings by the end of March.
After six months of hearings, a panel of 32 lawmakers this week recommended a ban on the face-covering veil in schools, hospitals, public transport and government offices, the broadest move yet to restrict Muslim dress in France.
The commission stopped short however of calling for legislation to outlaw the burqa in the streets, shopping centres or other public venues after raising doubts about the constitutionality of such a move.
France is home to Europe's biggest Muslim minority but the sight of fully-veiled women remains rare. Only 1,900 women wear a niqab, 90 percent of them under 40, according to interior ministry estimates.
Supporters of a ban argue that the full veil is being pushed by radicals in the French Muslim community, but critics say the wearing of the garment remains marginal and warn a ban risks stigmatising France's six million Muslims.
In 2004, France passed a law banning headscarves and any other "conspicuous" religious symbols in state schools after a long-running debate on how far it was willing to go to accommodate Islam in its strictly secular society.
The new French debate on the face-veil is being closely watched, three months after Swiss voters approved a ban on minarets.
President Nicolas Sarkozy set the tone in June when he declared the burqa "not welcome" in France.
He has since sought to reassure France's Muslims, declaring this week that freedom to practise religion was enshrined in the French constitution.
French support for a law banning the full veil is strong: a poll last week showed 57 percent are in favour.
The leader of Sarkozy's right-wing party in parliament, Jean-Francois Cope, has already presented draft legislation that would make it illegal for anyone to cover their faces in public on security grounds.The Netherlands and Austria are considering a ban on the full veil, while Denmark said Thursday it would limit the use in public of the burka and niqab veils although stopping short of an outright ban
France 24
