G8 leaders has promised $20bn (£12bn) of loans and aid to Tunisia and Egypt over the next two years and suggested more will be available if the countries continue on the path to democracy. David Cameron revealed he had intervened to prevent the package from being presented as more generous than it was in reality, suggesting that some at the G8 had wanted to present it as worth as much $40bn. "I argued through my officials that we should stick to the lower figure," said the prime minister, warning that if the higher figure had been used, "people go through it, realise that it falls apart, and that is actually very damaging to the whole process, which is why the lower figure is in there." The $20bn is being provided by multilateral institutions such as the World Bank, the IMF and, for the first time, the European Bank for Reconstruction and Development (EBRD). Cameron described the money as an investment in success and part of an enduring partnership. "If we get this wrong, if we fail to support these countries, we risk giving oxygen to the extremists who prey on the aspirations and frustrations of young people. If we fail we would see more terrorism, more immigration and more instability coming from Europe's southern borders and that affects us back at home," he said. President Nicolas Sarkozy of France said that in addition to the $20bn of credits, there would be as much again from other sources – $10bn from Gulf Arab states and $10bn in bilateral aid. Both Tunisia and Egypt told the G8 that their declining economies, battered by political instability and loss of tourism, needed urgent help. "We are truly very satisfied with the very strong, clear and precise statements proffered by all of the G8 nations, and the financial institutions," said the Tunisian finance minister, Jalloul Ayed. "It's very clear that everybody wants to help us." An IMF report on Thursday said the external financing needs of oil-importing Middle East and north African states would top $160bn over the next three years. The EBRD said it was now expanding its mandate into north Africa and the Middle East. It could invest annually up to €2.5bn(£2.2bn) in the region by 2015, with €1bn going to Egypt, the biggest Arab country with a population of some 80 million, EBRD communications director Jonathan Charles said. "We are looking at what was really driving the Arab spring. This is not just the demand for democracy. It is the demand for a better way of life, a better economy, so we should be looking very practically at what we can do to create jobs," he said.