Australian Treasurer Wayne Swan on Thursday accused European leaders of being "well behind the curve" on work to address the eurozone's debt crisis and called for "political courage" to be shown. Swan said "dark clouds" appeared to be regathering over Europe after a period of relative calm on global markets and he criticised the region's leaders for squandering the chance to make inroads. "In a pattern now all too familiar, European politicians are still well behind the curve, having failed to take advantage of the months of relative calm," Swan told a Euromoney conference in Sydney. "There is no escaping the conclusion that Europe has a long and painful road ahead -- with the most likely scenario being rolling crises and volatility. "Put simply, what is required is some basic political courage. Leaders are elected to lead, and that's what Europe's leaders must do," he added. European heads are under growing international pressure to take bold action as the eurozone crisis increasingly threatens global growth prospects. The issue is expected to dominate next week's G20 talks in Mexico. European Commission president Jose Manuel Barroso warned Wednesday of a "defining moment for European integration" and said the EU was facing a "social emergency" as the popular anti-austerity backlash grew. France has warned Greece that it could be forced out of the eurozone if it fails to uphold bailout commitments after elections due Sunday which the leftist Syriza party stands a good chance of winning. Syriza has vowed to tear up the rescue deal and even parties that backed it now favour renegotiating its terms. Swan echoed calls from Germany and the European Union executive for an acceleration towards greater fiscal and financial union but said such moves must be balanced with a programme of growth and job creation.