Red Bull Team Principal Christian Horner believes the ever-increasing costs of running a Formula One team will mean the smaller teams will struggle to develop their 2014 cars.
Horner added that the new engine regulations that came into effect ahead of the start of this season have come at 'exactly the wrong time'.
"The problem with the rule change at the moment is that it's probably exactly at the wrong time to do it," Horner told ESPN in Jerez, where the season's first pre-season testing session is taking place this week.
"It's hugely expensive and probably the biggest and most expensive rule change we've had that I can remember in Formula One.
"Obviously Formula One has to move with the times, has to be relevant with the automotive sector to maintain interest from the automotive suppliers, but one has to question the timing of this introduction because there are a lot of cars without stickers out there. It's inflicting a great deal of cost for the customer teams, the works teams less so, but for the customer teams there is a significant impact."
Horner added that a large portion of the teams' budgets would be spent on engine development, although he admitted that it is impossible to predict how much costs would rise this season.
"From a technology perspective it's fascinating and they're pieces of art, they really are," he added.
"It's incredible what the engineers have come up with, but as is usually the case when you allow engineers to come up with regulations, cost is not always at the top of their priority list. Hopefully over time as things settle down and homologation sets in costs will settle down.
"It's impossible to predict because it's not just the engine, it's the ancillaries that go with it. You could be looking at 20%-25% increase."