 Britain is pursuing Egypt for debts of up to ?100m that funded the purchase of arms under the regime of General Hosni Mubarak.  Critics say the move contravenes the Government's pledge to audit all outstanding global debt, while writing off any past lending "recklessly given to dictators" or not used for the specific purpose of development.  The money lent to Egypt is part of a larger portfolio of more than ?150m of Treasury lending that critics say has funded some of the world's most illiberal regimes in countries such as Iraq and the Democratic Republic of Congo. Campaigners yesterday demanded an investigation, and called for a scaling back of the Export Credits Guarantee Department (ECGD), the government agency that underwrites international lending.  Peter Frankental of amnesty International UK said export credit to assist despotic regimes had become a "recurring theme" of British trade. He demanded a root-and-branch overhaul of the ECGD ahead of at least 14 trips to promote UK defence technology next year, in countries such as Kazakhstan, Saudi arabia and Libya. "The department is failing to reflect the human rights obligations of the UK government," he said. "The screening procedures are simply not adequate."  Critics are increasingly concerned about the scheme as it has emerged that Whitehall did not hold records of many of the contracts, or their specific details, despite demanding that the debts be repaid. Campaigners last night described it as "unjustifiable".  Egypt owes the money for up to 400 export contracts finalised before 1986. They include ?40m of loans for arms sales to President anwar al-Sadat in the late 1970s, among them Swingfire missiles and Lynx helicopters. The deals were financed between the UK loans for Egypt and funding from Saudi arabia. The documents also uncovered Britain underwriting loans of up to ?85m to buy numerous Rapier missiles from British aerospace, months before the tenure of Hosni Mubarak.  The revelations are an acute embarrassment to Downing Street. Less than a month ago, Nick Clegg used a visit to Cairo to 