At the turn of the new year, just weeks after Greensill Capital was trying to convince investors it was worthy of a multibillion-dollar stock market debut, US court filings show its executives were engaging in “increasingly frantic conduct” as they scrambled for cash. Among them was Greensill’s vice-chairman, Roland Hartley-Urquhart, who court documents claim was chasing a large borrower for emergency payments and additional fees. The supply chain lender, which recruited the former UK prime minister David Cameron and a clutch of other high-profile politicians, bankers and former mandarins to promote its business, was reeling after insurers said they would not be renewing key contracts that kept Greensill’s complex money-making machine afloat. This is the picture painted in a claim submitted to a US court by one of Greensill’s largest former clients, with whom it is now in dispute. The US coalminer Bluestone is suing Greensill, its founder, Lex Greensill, and Hartley-Urquhart for claims including breach of contract, fair dealing and alleged fraud. The firm claims that starting last November, it suddenly came under pressure to make early repayments to Greensill on the $850m (£612m) it had borrowed from the business, causing it material and reputational harm. Lawyers for both parties have been summoned to a case meeting in New York on 1 June. Lex Greensill said in a statement: “This typically opportunistic lawsuit has only one aim, to avoid paying back more than $850m owed to the Greensill estate. It is also worth noting that in the month since it was filed in New York, no defendant named in it has been served.” Greensill’s administrators at Grant Thornton and Hartley-Urquhart both declined to comment. Bluestone’s lawyers did not respond to requests for comment. Parliament’s influential Treasury committee will begin to pick over Greensill’s operations on Wednesday it opens its investigation into the scandal. It will invite Greensill, Cameron and the chancellor, Rishi Sunak, to give evidence. Ahead of those hearings, Bluestone’s complaint appears to shed light on the conduct of Greensill managers during the final months before it filed for insolvency in March. The complaint also reveals an extraordinary business model, in which the firm loaned money to clients on questionable terms, in what MPs last week described as an apparent “Ponzi scheme”. Based in West Virginia, Bluestone mines and refines coal used in the steel industry. It was taken over by the billionaire governor of West Virginia, Jim Justice II, in 2015. According to the complaint, Hartley-Urquhart first reached out to Bluestone through a mutual business contact in May 2018. The company was in the midst of crafting an expansion plan, and claims it was looking for a partner to help realise its long-term investment ambitions. Greensill agreed to make the company two types of loan. According to the filing, the first type was traditional supply chain finance: money advanced by Greensill on invoices for goods – for example, shipments of coal – sold by Bluestone but not yet paid for. The miner borrowed $70m under this facility. A much greater sum, $780m, was borrowed under a more unusual scheme described as “prospective receivables”. Greensill, it is alleged, presented firm with a list of potential buyers of its coal, asking it to “identify those buyers Plaintiff believed could potentially be buyers of Bluestone’s … coal in the future”. The list included “both existing customers of Bluestone and other entities that were not and might not ever become customers of Bluestone”. The money loaned was against sales that had not yet happened, and might never happen. Bluestone claims this unusual form of financing was based on its “long-term business prospects”. It says it was led to believe that the loans would be rolled over when they fell due, and that Greensill would not begin calling in the debts until 2023 “at the earliest”. In March 2020, as the pandemic hit, Bluestone claims the lender “extended that financing commitment to a six to eight-year period” which induced them to “continue to expand their exposure to and deepen their dependency on Greensill Capital”. In return for the loans, Greensill is alleged to have collected $108m in upfront fees and eventually a further $100m in claims over shares in Bluestone. Greensill was not lending its own money. It acted as an intermediary, packaging the debt of companies such as Bluestone and selling it on to other investors, such as Credit Suisse. The Swiss bank’s clients bought up the debt, earning interest on their investments. By late 2020, Greensill was under pressure. In September, its Australian insurance underwriter told it that coverage for packaged loans sold off to investors such as Credit Suisse would not be renewed, in a move that threatened to bring down the lender’s complex structure. Despite the concerns, Greensill pressed ahead with plans for a stock market floatation. Towards the end of 2020, it visited a number of private equity houses to tout its credentials as a tech giant. Leaked marketing materials from the start of 2020 placed a confident $30bn valuation on Greensill. Bluestone’s complaint appears to suggests that given Greensill and its advisers were touting for investment, panic may have already set in. Bluestone claims Hartley-Urquhart became “increasingly frantic”, demanding additional fees, and faster repayment of debts. According to Bluestone, Greensill’s approach changed abruptly and “without explanation”. At the end of November 2020, Greensill demanded a new $15m fee, allegedly saying the income was important to help launch its IPO. It then allegedly pushed the borrower to sell junk bonds to raise enough money to pay Greensill back in full by July 2021. Bluestone said the date was arbitrary and not referenced in any of its loan agreements. Hartley-Urquhart continued to chase Bluestone in January and February this year, even asking it to wire money directly to Credit Suisse, so that it could blame Bluestone for its own late payments. Bluestone says it had no idea Greensill had transferred its debts to the Swiss bank. On 20 February, on a visit to White Sulphur Springs, West Virginia, Hartley-Urquhart demanded Bluestone cough up $300m by September. Within days, Greensill was demanding the entire $850m be repaid by the end of the third quarter. On 1 March, Hartley-Urquhart called Bluestone to confirm Greensill Capital had collapsed and that he would be leaving the business. Greensill Capital filed for administration on 8 March. It faces a criminal complaint by prosecutors in Germany. The Treasury committee hearing is one of eight inquiries that have been launched in the UK linked to Greensill’s lobbying efforts, lending practices and its regulation in Britain.