German Chancellor Angela Merkel defended her handling of the Greek debt crisis today, saying a decision on aid could not have been made any earlier, according to dpa. Merkel spoke as a bill to approve Germany's 22.4-billion-euro (29- billion-dollar) share of the joint eurozone and International Monetary Fund (IMF) package was introduced to parliament, with a vote due by Friday. "A decision could not have been taken without sufficient concrete details of the savings plan," Merkel said. "That would only have led to rising expectation that highly indebted members of the eurozone could count on generous financial help without their own consolidation efforts." The bill passed an important hurdle when the parliamentary budget committee gave its approval later in the day, virtually ensuring that parliament will vote in favour on Friday. European Central Bank governing council member Axel Weber on Wednesday warned German parliamentarians that a Greek default would threaten the stability of Europe's currency union. "There is a threat of serious contagion effects for other eurozone countries and increasing negative feedback effects for capital markets," he said. Weber, who also heads up Germany's central bank, the Bundesbank, described Germany's contribution to the bailout as justifiable. But the largest opposition group, the Social Democrats (SDP), were still "highly unlikely" to vote in favour of the bill, party sources said. The radical Left Party have come out against the bill, while the Green Party remained undecided. Nevertheless, the parliamentary majority of Merkel's governing coalition of Christian Democrats and Free Democrats should ensure the bill is passed into law, in time for a eurozone summit scheduled Friday. Markets around the world fell sharply on Tuesday, as the passage of the 110-billion-euro aid package for Greece failed to reassure investors. The euro on Wednesday remained beneath a one-year low. The German cabinet had signed off on the bill Monday, as Greece finished negotiations with the IMF on a further round of harsh budget cuts. Germany is the largest single contributor to the aid package. "Today Europe is looking at us. Without us, or against us, there won't be any decision," Merkel said. However, the chancellor has been blasted by domestic opposition and eurozone partners for delaying German approval of the aid package until the last minute. A key regional election in the state of North Rhine-Westphalia is set for Sunday. "She dithered ... and then claimed it afterwards as strategy," SPD caucus leader Frank-Walter Steinmeier said. On Tuesday, German banks led by Deutsche Bank said that they would participate in the bailout - responding to calls from the opposition - by remaining in Greece and being prepared to keep lending to Athens. A day later, however, Merkel warned banks that their participation would not result in a payoff, such as the proposed financial transaction tax being dropped. "If the banks think that ... they will be spared the bank levy or other measures, they have deceived themselves," Merkel said. She told parliament that the conditions of German aid being released - primarily that Greece put forward a credible savings plan and that it be approved by the International Monetary Fund and European Central Bank - had been fulfilled.