Eleven major brokers have decided to pool resources in their patent dispute with Roderick Lawrie, the owner of InCom Licensing.
The action group includes The AA, Allen & Allen, Endsleigh, Confused, BDML, Budget, Swinton, inspop, Hastings, DirectChoice and Kwik-Fit.
Inventor Lawrie claims to own the patent on software that searches for best product prices on the internet (see Insurance Times, 10 April).
Consequently, Lawrie is demanding that any broker running such a system should pay between £50 and £100 per terminal per year or be shut down.
But the group of brokers has decided to share their legal advice and other resources to defeat what a BDML spokesman called "the bizarre and totally unenforceable requests that Mr Lawrie has based on his supposed patent".
"Some of the intermediaries have already been advised of the many and various ways in which they do not infringe the patent," said the spokesman.
"There is also a move to challenge the patent itself and to have it declared invalid."
Other businesses that could be forced to pay fees for using the software include online travel, accommodation and car sales.
If Lawrie is successful in getting companies to pay charges for using the software, he expects to receive £50m within 12 months.
But Lawrie's initial target of collecting £1.5m in fees by the end of May has been missed.
"That hasn't happened, as larger companies have resisted paying, though smaller companies are paying up," said Lawrie.
"Some of the bigger players are coming forward and saying they need more time to pay the fees.
"When it comes to the bigger companies, the fees involved can be in the region of £250,000 per year."
Lawrie said that a number of companies had been given a grace period until the end of this month.
He said that brokers would be unsuccessful in their attempts to declare the patent invalid.
"That could not happen as we already have the patent as it has been granted."
But a source said that the major software houses had recently met and decided to fight Lawrie on the grounds that there was prior art (other patents that pre-date Lawrie's claim).