Chancellor Angela Merkel said Friday the stability of the European single currency needed to be secured, after parliament approved Germany's 22.4-billion-euro (28.5 billion dollars) share of a Greek bail-out package, according to dpa. Germany is contributing the largest single portion of the International Monetary Fund-eurozone rescue package for highly- indebted Greece, which is set to amount to 110 billion euros over three years. An EU summit later Friday is now due to sign off on the complete rescue deal. "In Brussels we will discuss the activation of this programme so that the security of the euro is guaranteed," Merkel said at a press conference in Berlin. Merkel's centre-right coalition, with the support of the Green party, carried the vote in the lower house or Bundestag, which passed with 390 votes in favour, 72 against and 139 abstentions. "We must defend our common European currency ... and at the same time defend the whole European project," Finance Minister Wolfgang Schaeuble told the assembly before the vote. The Bundestag vote came after global markets tumbled overnight on fears of the Greek debt crisis spreading to other euro members such as Portugal and Spain. The single currency managed to rebound more than 1 per cent in trading Friday, despite a further fall in shares. In Berlin, Merkel asserted that the common purpose of the European Union had to come above the vacillations of the markets. "We will also lead a fundamental discussion ... which has to make clear that politics has absolute priority in ensuring the stability of the euro," she said. Merkel blames financial speculation for worsening the Greek crisis. As Merkel spoke the bill was being debated by the Bundesrat, the upper house of parliament representing Germany's federal states. Passage is virtually assured, however, as a majority of state premiers have already said they will approve the bill. President Horst Koehler would then sign the bill into law later Friday. A group of five high-profile lawyers - known as the "euro rebels" - Friday attempted to halt the bail-out package by appealing to the constitutional court, arguing that the bill breached European Union law, as well as German constitutional rights. The government has said it considers the move highly unlikely to succeed. The constitutional court may reach a decision over the appeal during the weekend, a court spokeswoman said. Four of the five claimants had previously appealed in 1998 against the introduction of the euro. The largest opposition party, the Social Democrats, abstained from the Bundestag vote, after their attempts to have stricter regulations for financial markets bound into to Germany's approval of the aid package were rejected by the government coalition.