The legislation passed with 230 votes in the 300-seat chamber.
Their reopening followed Prime Minister Alexis Tsipras' reluctant acceptance of a tough package of bailout demands from European partners
The country secured a euro 7.16 billion bridge financing from the European Financial Stability Mechanism
The crisis remains acute with the country's banks already closed.
Tsipras said the mandate that Greeks had given him was to reach a viable solution rather than clash with Europe
The result of the opinion polls would allow the government to move ahead quickly to reach a deal with creditors
Greek finance minister to hold talks with bankers on Sunday
The proposals appeared so far apart that success seemed higly unlikely
EU authorities made a last-minute offer to salvage a bailout deal that could keep Greece in the euro as the clock ticked down on Tuesday, with Germany warning that time had run out to extend vital credit lines to Athens.
The impending default on the IMF loans leaves Greece sliding towards an exit from the euro.
The IMF dashed any hope that Athens could avert default.
Banks were shut almost two weeks ago as the govt negotiated a 10 billion euro bailout package.