A group of hedge funds and investment banks seeking control of Delphi, the bankrupt car parts supplier, has attacked General Motors’ involvement in Delphi’s restructuring.

The investors, led by Appaloosa Management, have accused the parts maker of undermining its own refinancing by inviting GM to participate as a sizeable, secured lender in a $6.1bn financing package required to pay Delphi’s creditors and restructure its balance sheet before it can emerge from Chapter 11.