BERLIN (Reuters) - German Chancellor Angela Merkel's Bavarian allies have accused the Greek government of not having grasped the seriousness of the situation in the debt talks yet, with CSU Secretary-General Andreas Scheuer calling ruling politicians in Athens "clowns".The remarks were the latest sign of hardening positions towards Greece among European politicians, on the eve of a meeting of euro zone ministers that could be the last chance to rescue Greece from default at the end of the month.Scheuer said in an interview with Rheinische Post newspaper published on Wednesday that Greece had done too little so far to stay in the euro and there would be no "careless compromises" just for the sake of keeping Greece in the single currency bloc."The Greek government apparently hasn't realized the seriousness of the situation yet," Scheuer said."They are behaving like clowns sitting in the back of the class room, although they have received explicit warnings from all sides that they might fail to pass to the next grade."German Chancellor Angela Merkel said on Tuesday she was willing to do all she could to keep Greece in the euro zone but insisted the onus remained on Athens and its creditors to break a deadlock and reach a deal.Merkel is facing growing opposition among her ruling conservatives to granting Greece any further bailout funds. Germany is Greece's biggest creditor and the biggest contributor to the EU budget and the euro zone bailout fund.Klaus-Peter Willsch, a dissident lawmaker from Merkel's conservative party who repeatedly voted against bailing out Athens, told Deutschlandfunk radio on Wednesday that in his view it would be no big deal if Greece were to leave the euro zone."This wouldn't be the end of Europe," Willsch said.Greek Prime Minister Alexis Tsipras has accused creditors of trying to "humiliate" his nation, which is set to default on a 1.6 billion euro ($1.8 billion) debt repayment to the International Monetary Fund on June 30, possibly driving it towards the euro zone exit, unless it receives fresh funds.(Reporting by Michael Nienaber; Editing by Peter Graff)Join the conversation about this story Click here to read full news..