French President Nicolas Sarkozy said on Sunday he had not ruled out that Switzerland would be placed on a tax haven blacklist by 20 of the world's largest economies.
"Based on the actual state of things and on the rules, it could be, yes," Sarkozy said when asked whether Switzerland met the criteria for an uncooperative tax haven set by the Organisation for Economic Cooperation and Development (OECD).
German Chancellor Angela Merkel sounded more conciliatory regarding a possible resolution.
"So far I don't have a concrete idea about such a list," she told reporters in Brussels. "But I think the better we are in talks with each other the smaller the likelihood of such a list."
The Swiss Bankers Association described Sarkozy's comments as "sickening hypocrisy", adding: "The only name on the list that Mr Sarkozy seems capable of pronouncing is Switzerland."
Swiss President Hans Rudolf-Merz has said the country may need to make some concessions in banking secrecy, while Foreign Minister Micheline Calmy-Rey has said Switzerland is open to negotiations on the issue.
Leaders of the G20 will discuss the issue of tax havens when they meet in London in April. The G20 comprises countries and developing countries including China, India and Brazil. Switzerland was not invited to the meeting.
In a poll published by the German-language SonntagsBlick tabloid, 56 per cent of respondents said they favoured the Swiss government cooperating with foreign authorities on tax issues. One-third was opposed.