Switzerland's economics minister, Pascal Couchepin, says banking secrecy is non-negotiable. He has also come to the defence of the country's neighbour, Liechtenstein, under fire for failing to cooperate in the fight against money laundering.
Couchepin made the statement after attending a meeting of ministers from the Organisation for Economic Cooperation and Development, which groups the world's industrialised nations. The meeting covered a range of issues, but banking secrecy was by far the most sensitive for the Swiss.
The position that banking secrecy is not up for discussion had already been reinforced after last week's European Union summit in Portugal, at which EU member Austria was persuaded to show more flexibility in its own banking sector.
As a result of the EU agreement, states seeking membership of the body are asked to provide a free exchange of information relating to bank holdings. Switzerland, whose 1992 EU membership application was frozen the same year, is nevertheless affected by the decision.
The Swiss believe that they will be able to achieve a compromise that will satisfy all sides, without touching banking secrecy. The government hopes to gain something in return from the EU, such as the inclusion of Switzerland in the Schengen agreement, which allows free movement of people within Europe.
Couchepin warned Brussels against failing to respect Switzerland's position. "If the EU doesn't respect the small countries, then I wouldn't be sorry if the Swiss people said no to membership".
The minister also defended Liechtenstein, which has been blacklisted by the OECD and other international bodies for failing to crack down on money laundering. He said Switzerland's neighbour had made great strides towards controlling financial flows to and from its banks.
Switzerland, which has a customs and currency union with the principality, sympathised with its position, he said. He also said he believed Liechtenstein would do all it could to get itself off the blacklist of 35 countries under pressure to reform their financial systems.
swissinfo with agencies