Adrian Newey fears F1's decision to do away with the engine development tokens will lead to a "spending frenzy" and that Renault could be left behind.
The token system was brought in at the start of the V6 era to prevent out of control spending.
F1's engine manufacturers were given tokens to use in the off-season to upgrade their units but found a loophole that allowed them to continue developing throughout the 2015 season.
This year they once again have 32 tokens but next year they will have free reign as the system is set to be scrapped.
And Newey fears that will lead to out of control of spending that some manufacturers, namely Red Bull's engine supplier Renault, will not be willing to keep up with resulting in a bigger gap to the front.
"More spending, simple as that," the design guru told Reuters when asked about the decision to open up engine development in 2017.
"If you look back on the original technical working group meetings and minutes from 2012-13, the agreement at that point was that the engines would be frozen but teams that were behind would still be allowed to keep developing. That’s not happened.
"So it becomes a spending frenzy…the numbers being spent by the big manufacturers are eye-watering and so I think potentially for companies such as Renault who aren’t prepared to spend that sort of money, it means actually the gaps get bigger not smaller."
The Brit also weighed in on the relationship between F1's full works teams – Ferrari, Mercedes and Renault – and their customers saying that the latter seldom gets the exact same package.
"It’s very curious to me that we have this set of regulations where the manufacturer has to supply the same hardware to other teams but it’s no under no obligation to supply the same software and therefore the same performance," he said.
"Nobody is complaining about this because the customer teams can’t complain because their contract doesn’t allow them to."
Newey did, however, state that Renault had always been fair with Red Bull.
"They have always given the same power units in every sense of the word, including software, to their customer teams as their works teams.
"Of course it’s an option for Red Bull and it’s an option for Renault (to continue together).
"The problem of course is that if Renault are not able to compete with the spend and development race then we are put in a position where neither they nor us can be fully competitive."