The Australian Prudential Regulation Authority has ordered banks to conduct an "extreme and difficult" stress test to measure their capacity to stand up to any worsening of the European debt crisis.According to an article in the Australian Financial Review today, banks have been given a short turnaround to model what would happen if the European situation reached meltdown and its full impact hit Australia. The stress test scenario is said to include a 12 per cent unemployment rate, a 30 per cent decline in house prices and a 40 per cent fall in commercial property values.Australian banks have limited exposure to Europe, according to the paper. About A$90 billion of assets - mostly loans to banks in France Germany and the Netherlands - represents less than three per cent of assets.