Egyptian President Mohamed Mursi signed into law a new constitution shaped by his Islamist allies, a bitterly contested document which he insists will help to end political turmoil and allow him to focus on fixing the economy.Anxiety about a deepening political and economic crisis has gripped Egypt in past weeks, with many people rushing to buy dollars and withdraw their savings from banks. The government has imposed new restrictions to reduce capital flight.The new constitution, which the liberal opposition says betrays Egypt’s 2011 revolution by dangerously mixing religion and politics, has polarized the Arab world’s most populous nation and prompted occasionally violent protest on the streets.The presidency said on Wednesday that Mursi had formally approved the constitution the previous evening, shortly after results showed that Egyptians had backed it in a referendum.The text won about 64 percent of the vote, paving the way for a new parliamentary election in about two months.The charter states that the principles of sharia, Islamic law, are the main source of legislation and that Islamic authorities will be consulted on sharia - a source of concern to the Christian minority and others.The referendum result marked yet another electoral victory for the Islamists since veteran autocrat Hosni Mubarak was toppled in 2011, following parliamentary elections last year and the presidential vote that brought Mursi to power this year.Mursi’s government, which has accused opponents of damaging the economy by prolonging political upheaval, now faces the tough task of building a broad consensus as it prepares to impose austerity measures.The Egyptian pound came under renewed pressure on Wednesday as market players, worried about the economy, switched their funds into U.S. dollars and other currencies, traders said.Keen to be seen as decisive, the government is now in talks with business figures, trade unions and other groups to highlight the need for tax increases to resolve the crisis.Mursi has committed to such austerity measures to receive a $4.8 billion loan from the International Monetary Fund.