Prime Minister Alexis Tsipras fought to contain a backlash from his own leftwing party on Wednesday as parliament prepared to vote on a sweeping austerity package European partners have demanded for a new bailout to keep Greece in the euro. The ruling Syriza party, elected in January on an anti-austerity platform, has been deeply split by the bailout deal that a reluctant Tsipras was forced to accept after gruelling negotiations in Brussels this week.