Switzerland's parliament would not vote for a second tax treaty to help settle U.S. charges that Credit Suisse bankers helped wealthy Americans evade taxes, Swiss politicians were quoted as saying on Sunday.

In 2009, the Swiss government cut a deal with Washington to hand over the details of 4,450 UBS bank accounts to the U.S. authorities to end a damaging lawsuit against the bank, lifting the veil on Switzerland's cherished tradition of banking secrecy that had helped it build up a multi-trillion-dollar offshore banking industry.

But politicians of various affiliations said there was little appetite for a second deal to help Credit Suisse, which is being probed by U.S. authorities as part of a broader investigation into banks suspected of helping Americans evade taxes.

The enthusiasm to guarantee a bank state help again is very low, Christian Democrat (CVP) Pirmin Bischof was quoted as saying in the SonntagsZeitung.

This view was echoed by Free Democrat (FDP) Ruedi Noser in the NZZ am Sonntag newspaper.

Parliament will not accept a second state treaty, he said.

Offshore tax havens have come under attack in recent years as cash-strapped governments seek to boost revenues in the wake of the financial crisis, forcing countries like Switzerland to pledge to cooperate more to help hunt tax cheats.

Last week U.S. authorities indicted three Credit Suisse private bankers for allegedly helping wealthy Americans evade taxes, bringing the total number of Credit Suisse bankers indicted to seven.

Despite their insistence Credit Suisse must solve its problems alone, the growing scrutiny from the U.S. has angered some politicians, potentially straining talks between the two countries on a multibillion dollar deal over Swiss banks helping Americans to shield their money from the U.S. taxman.

If the U.S. is going to act in such a way Switzerland must break off negotiations for a political solution, Noser was cited as saying in the NZZ am Sonntag.

The talks had already become bogged down due to Swiss insistence any deal leave Swiss bankers free from prosecution in the United States, sources said last month.

The investigation against Credit Suisse has also prompted Swiss private banks Sarasin and Julius Baer to ban staff from traveling to the United States.

For the last two weeks it has been necessary to get approval for all private and business trips to the U.S., Sarasin spokesman Benedikt Gratzl told der Sonntag.

It's about protection. So the bank and its employees will be protected from investigations and arrests, Gratzl said.

Julius Baer declined to comment to the paper and did not immediately respond to a request for comment from Reuters.

(Reporting by Caroline Copley; Editing by Erica Billingham)