PARIS: France denied on Monday it was planning an amnesty for up to 3,000 citizens on a list of suspected tax evaders in Switzerland, but said offenders would be given a one-off chance to come clean with the taxman.

Budget Minister Eric Woerth revealed in an interview at the weekend that Paris had obtained the names of 3,000 French taxpayers with assets in three Swiss banks worth a total of about three billion euros (4.3 billion dollars).

He told the Journal du Dimanche newspaper that at least some of the 3,000 were "very probably" tax evaders, who would be given until December 31 to pay any overdue tax -- after which they would face a full tax audit.

"We are not bluffing, we have a list of 3,000 names," Woerth told France's Radio Classique on Monday, although he said the government would not publicly name the banks nor the individuals concerned.

Left-wing opposition leaders immediately accused President Nicolas Sarkozy's right-wing government of planning a mass amnesty for tax evaders, but Woerth denied that offenders would be let off the hook.

"Of course there is no amnesty. When I call on people to square their situation with the authorities, that means they will pay tax. An amnesty is to pay no taxes, or very low taxes, which is not the case," he said.

The announcement comes two days after France signed an accord with Switzerland on data exchange to clamp down on tax cheats, in line with rules laid down by the Organisation for Economic Cooperation and Development.

Woerth told the Journal du Dimanche that most of the names had been obtained from the Swiss tax authorities, and others directly from the banking establishments concerned.

Faced with international pressure, Switzerland announced this year it would make excpetions to its banking secrecy rules in order to offer other countries more help on matters involving cross-border tax offences.

Banking secrecy laws traditionally prohibit Swiss banks from revealing information about their clients, except as part of a criminal investigation.

In Switzerland, only tax fraud is regarded as a crime, not tax evasion which is treated only as a more minor offence, a judicial distinction which does not exist in most other major economies.

But under its new deal with France, Switzerland agreed to offer assistance on all tax offences, as long as there is evidence of tax violations.

Similar deals have been negotiated with a string countries including Japan, the United States and Britain. Most still have to be ratified, while three -- with Denmark, Luxembourg and France -- have been signed.