Helphire returns to the Court of Appeal on Monday to seek a settlement in up to 20,000 credit hire cases still left unresolved despite the Dimond v Lovell ruling in May.
The legal action follows Helphire's failure to reach a negotiated agreement with Royal & Sunalliance and CGNU in thousands of disputed credit hire cases worth a reported £80m.
Mark Jackson, Helphire deputy chief executive, said: "The case is an attempt to clarify points of law which had been left out of the Dimond v Lovell judgment."
He expects the hearing to last up to three days and said it would focus on a sample of the disputed cases to test the enforceability and level of charges of its credit hire agreements.
Helphire has been in talks to reach a settlement with a number of insurers and it sealed an agreement with Direct Line in 1,000 credit hire cases in October.
At the time of the agreement, Helphire's chief executive Michael Symons said its stubborn negotiating tactics had paid off.
"We had to take a hard stand initially in order to get to a position where there was an incentive to settle."
Helphire also agreed to abide by the terms of the Association of British Insurers' code on credit hire for all post-Dimond v Lovell claims involving Direct Line.
Details of this deal are set to be reported in the credit hire company's half-year results at the end of November.
Helphire chairman Martin Kinney has warned the group may be unable to match its pre-tax profits of £6m last year.