ZURICH (REUTERS) - Swiss upper house lawmakers on Wednesday backed draft law that would let Swiss banks hand over information to the US authorities to help settle a dispute on tax evasion.

The approval for the government bill, the upper chamber's second in two weeks, puts the final say on the bill with Switzerland's lower house, which on Tuesday refused to address it.

With the draft law increasingly unlikely to be fast-tracked before the end of parliament's summer session on Friday, government officials and lawmakers scrambled to mitigate the potential fallout for Swiss banks.