As many as four teams could be missing from the Formula 3 European Championship grid in the 2016 season.
With the FIA championship's deadline for entry registration looming on Monday, Fortec Motorsport, Double R Racing and Signature are set to abandon Euro F3, with Team West-Tec waiting on a possible last-minute deal to run one driver.
The entry list looks set to be down considerably on 2015's record-breaking 36 cars, with Autosport estimating a grid of between 20 and 25.
West-Tec engineering chief Mick Kouros laid the blame at the door of technical regulations that he says have allowed bigger teams - Prema Powerteam, Hitech Grand Prix and Van Amersfoort Racing all enjoy input from wealthy investors - to develop expensively.
"The grey areas within the FIA regulations have allowed aero developments to be exploited where the smaller teams can't afford to compete," said Kouros.
"Drivers are looking at other things where they feel they can be competitive, because in F3 they feel they can only drive for one of the big three."
Fortec boss Richard Dutton told Autosport: "We're talking to drivers but there don't seem to be any with a budget.
"It's thin out there: unless something happens over the weekend I'm not going to put in €21,000 per car for an entry.
"I think the FIA have overestimated the market - they seem to think there are a lot more drivers out there than there are.
"We've got two cars ready for FIA, but we're looking at following Carlin and doing two in Euroformula Open [for current Dallara chassis with spec Toyota engines], which you can do for virtually half the money, and we could convert them back for Macau.
"It's really sad we can't find drivers for FIA and we won't quit F3 for sure, but we have to do whatever the market demands."
Double R principal Anthony Hieatt, who will keep his cars for the Masters of F3 and Macau GP, added: "I've switched off the Euro F3 programme now - MSA Formula and BRDC F4 is us.
"I'm not interested in doing it on a wing and a prayer and making these billionaire boys look better."
French team Signature could not be contacted for a comment.