Renault chiefs have launched a scathing attack on the introduction of KERS (Kinetic Energy Recovery Systems) in Formula One this year - claiming they are dangerous and too expensive.
As teams continue preparations of the devices in pre-season testing, Renault team principal Flavio Briatore has labelled the use of them in Formula one as a 'terrible mistake'.
And his technical director Bob Bell has expressed fears of a KERS accident this season - with perhaps a mechanic suffering an electric shock like happened to a BMW mechanic during testing last year.
Renault are scheduled to introduce their own KERS for the first race of the season in Australia, but that has not stopped Briatore and Bell criticising the idea of using them.
Bell, who says the team are undecided yet on whether KERS will run in Australia, is fearful about the possibility of an incident with the systems this year.
When asked at the launch of the team's new R29 in Portugal on Monday if he had any safety concerns about KERS, he said: "Very much so. It's unknown territory for us.
"We are not used to seeing cars with high voltage stickers. I think there will be some accidents this year. It's inevitable. And you'll probably see some mechanics get nasty shocks. Let's hope it's no more than that. The same could be said of marshals.
"The sport has done a very good job of trying to minimise the risk, to mechanics, technicians and trackside people, but there is still a risk. It's several hundred volts and the potential to be tens of amps, so it's pretty lethal. And it's DC (direct current), so if you hold it you cannot let go."
Briatore is deeply unhappy about the amount of money his team have had to spend on KERS, especially against the backdrop of the worldwide economic crisis.
"I think it is a terrible mistake," said Briatore. "In the end Renault, Mercedes-Benz and Ferrari supply engines to other teams, and we are not making any money - it is costing us but we are doing it for the good of F1.
"We have the big reduction in the costs of engines, but in another way we have opened the door on something else. We don't know how much it is going to cost us in the end with development, and we don't know if it is dangerous or not - it looks like it is not 100 percent in control.
"And does it bring any good to us? What it brings to us is only cost, that is sure."
Briatore has criticised rivals BMW Sauber for not backing a proposal put forward at the Chinese Grand Prix last year for a delay in the introduction of KERS. Their decision meant that other teams were forced to keep developing their own devices in readiness for this season.
"We have this situation because one team only was determined to take this programme," explained Briatore.
"We know already for 2010 there is an option for a standard KERS - so whatever money we spend this year is for one year only. In this kind of environment it is completely unnecessary what we are doing. Plus, if you ask about performance - nobody knows. If you ask me, better with KERS or better without KERS? That is a big question mark.
"But for sure BMW wanted to go to the end, so we had to follow that. It is difficult for us to have one competitor developing a programme and we are not part of it. We are talking about performance, but in this moment to support such a programme brings no good to anyone. What we know is we spend a lot of money for nothing. That is for sure."