Delphi and its backers have accused a group of hedge funds of holding General Motors and the US government to ransom by challenging a deal to sell the bulk of the bankrupt parts maker’s assets to Platinum Equity, a California-based private equity firm.

In filings with a New York bankruptcy court on Thursday, Delphi, Platinum and their advisers insist the deal is the only realistic option that has emerged in almost four years since Delphi, GM’s biggest supplier, sought Chapter 11 protection.