France's hard-line new immigration minister is set to implement legislation that would allow DNA testing of new arrivals.
Eric Besson, who was appointed this month, has said the tests would establish which foreigners were claiming visas by making up fictious family ties with those already settled in the country.
Civil liberties groups have reacted furiously to the controversial scheme, which was approved by the French parliament 15 months ago but does not come into effect until the appropriate minister has signed the legislation.
Until now that move had been delayed by protests.
But Mr Besson has now said he wanted to give it the ‘green light’, confirming that a ministerial meeting would be held on the subject ‘in a few days’.
He added: ‘If the decree is accepted, I will scrupulously respect all individual liberties. It’s not my obsession.'
The tests will be for applications for visas of more than three months when there are doubts about an immigrant's birth or marriage certificates.
The move would allow officials to 'propose' to applicants that they take a test at their own expense to prove a biological link with other family members.
A recent report said there was often doubt over the authenticity of papers in family applications for visas.
It claimed that in African countries such as Senegal, Ivory Coast and Togo up to 80 per cent of birth and marriage certificates were forged.
Government statistics show there are 23,000 immigration cases a year where visa applications involve children, meaning DNA tests would become widespread.
But immigrant welfare groups said the plan was unacceptable.
Daniele Lochak, a former president of GISTI, a group providing information and support for immigrants, said: ‘It's obvious that applicants who refuse DNA tests will have every chance of having their visas refused.’
The cost of up to £350 for a test is also likely to be beyond the reach of many immigrant families.
France has strict controls on DNA testing. Its civil code says studies of a person's genetic characteristics can only be for medical or scientific research, meaning magistrates will have to authorise the new immigrant tests.
Outgoing immigration minister Brice Hortefeux recently announced that France deported 30,000 illegal migrants in 2008 - a record number.
It was a rise of more than 25 per cent on the number expelled the previous year.