German Finance Minister Wolfgang Schaeuble called on opposition parties Wednesday to vote in favour of the rescue package worth up to 100 billion euros ($123 billion) for beleaguered Spanish banks.
"We hope the SPD (Social Democrat) and (environmentalist) Green parties will assume their European responsibility" when the vote is held in parliament on Thursday, Schaeuble told the regional daily Rheinische Post in an interview.
German MPs are being dragged back from holiday to vote on the rescue package for Spanish banks after the country's constitutional court ruled that parliament must be consulted every time the eurozone's current bailout fund, the EFSF, is pressed into action.
Even though a handful of Merkel's own political allies may rebel, the package is expected to be passed with a large majority after opposition parties have already signalled they will vote in favour.
Schaeuble was similarly confident.
"We need a simple majority. But we want as great a degree of agreement as possible within our own ranks," he said.