In a civil fraud case in New York, Donald Trump was forced to pay $464 million (£365 million), but he is unable to locate a private firm to guarantee the money. To proceed with his appeal, the former president needs to either obtain a bail or pay the entire sum in cash. Mr Trump's lawyers said on Monday that securing a bond of that size was a "practical impossibility". For a fee, a bonding company would guarantee the full amount to the New York court. They would then have to pay it if Mr Trump loses his appeal and cannot do so himself. Mr Trump's team spent "countless hours negotiating with one of the largest insurance companies in the world", the lawyers wrote in a court filing, but concluded that "very few bonding companies will consider a bond of anything approaching that magnitude". The lawyers said they had approached 30 companies without success. Mr Trump's two eldest sons also must pay millions of dollars in the case. Along with ordering Mr Trump to pay the penalty, New York Judge Arthur Engoron banned him from running any businesses in the state for three years after he found the former president falsely inflated assets to secure better loan deals. A judge paused Mr Trump's business ban last month, but denied his bid to provide a smaller bond amount to cover the fine. In the latest filing, the former president's lawyers included an affidavit from a president of a private insurance firm, who said that "simply put, a bond of this size is rarely, if ever, seen". "In the unusual circumstance that a bond of this size is issued, it is provided to the largest public companies in the world, not to individuals or privately held businesses," the lawyers also said. Mr Trump's team added that they had spent "countless hours negotiating with one of the largest insurance companies in the world" with no success. They also said bond companies would not accept "hard assets such as real estate as collateral" for the bond, but only cash or "cash equivalents", such as investments that can be quickly liquidated. According to a Forbes estimate, Mr Trump is worth about $2.6bn. He also testified last year that he had $400m in liquid assets. But the $464m judgement is not his only expense. He was ordered to pay $83m in January after losing a defamation case to E Jean Carroll, a woman he was found to have sexually abused. He has already posted a bond in that case. New York's attorney general has vowed to seize his assets if he does not pay the fraud penalty. The penalty will keep accruing interest by at least $112,000 per day until he pays.