The lower house of parliament in Switzerland has refused to debate a bill that would allow Swiss banks to pass client information to the tax agencies in the United States.
The bill is the result of pressure from the US after disclosures that Swiss banks helped American account holders to evade taxes.
The US demanded action by 1 July, but the BBC reports the Swiss parliament summer session ends this week. The bill will now return to the Senate.
The lower house decided by 126 votes to 67 not to discuss the bill. A second rejection by the lower house would effectively kill the draft law.
The bill would allow Swiss banks to sidestep strict secrecy laws and release information relating to clients' accounts.
It also contained secret clauses requiring the banks to pay an estimated $10bn (£6.4bn) in compensation for lost tax revenue.
A BBC correspondent said Swiss politicians are in no mood to change their laws because Washington tells them to.
In January Switzerland's oldest private bank, Wegelin, closed after being indicted and fined $US58 million after admitting in court to helping American customers to hide more than $US1.2 billion from the Internal Revenue Service.
In 2009, Swiss bank UBS paid $US780 million and handed over details of more than 4000 accounts in order to avoid indictment.