Switzerland's upper house of parliament voted on Tuesday after a heated debate to approve retrospectively the 109 billion Swiss francs ($120.5 billion) in financial guarantees used to rescue Credit Suisse last month.

Lawmakers were recalled for a rare extraordinary session to discuss the rapid rescue of Credit Suisse and the Swiss government's open chequebook response to a collapse which many in the country have blamed on top management.

A shotgun marriage which saw Credit Suisse taken over by Zurich-based rival UBS for 3 billion Swiss francs and propped up with more than 250 billion Swiss francs in guarantees and support has been the subject of widespread criticism.

But 29 of Switzerland's 46-member Council of States upper house approved the measure. The Swiss parliament's lower house is scheduled to vote on the matter later on Tuesday in a session likely to go until midnight local time (2200 GMT).