Formula 1 cannot afford to remain with fully frozen engines if the sport is going to be more exciting in the future, says Red Bull boss Christian Horner.
As pressure mounts on Mercedes to end its opposition to an easing of F1's engine freeze rules, Horner reckons that changing the regulations is vital for the health of grand prix racing.
"For F1 it is important," he said. "We saw Nico Rosberg's performance [in Russia] - the true performance is they can drive through the field. It is too out of kilter.
"There were five Mercedes-powered cars in the top five, and the immaturity of this technology is still quite raw.
"I think Mercedes should not be afraid of competition, they are doing a super job.
"But it is healthy for F1 that Ferrari, Honda and Renault should have that ability to close that gap otherwise we are going to end up in a very stagnant position."
Mercedes has made it clear that it will not approve the changes to the rules for 2015.
And with unanimity required at the F1 Commission for it to happen, there appears no chance of it going through unless Mercedes can be convinced to change its mind.
When asked what could be done to persuade Mercedes, Horner said: "I think it is a bigger issue than just about the teams.
"It is about what is right for the sport, what is right for the fans.
"It is easy to take a self-interest position, but when you look at what is the right thing for F1, it is to have competition.
"We need to be big enough to say let's open it a little bit, and let's be responsible on costs - so there is no cost impact for customer teams - but have that competition."
When asked about the potential danger of Mercedes actually pulling further clear if the engine freeze is relaxed, Horner added: "It is quite possible.
"But at least you have the ability to try to improve because at the moment you are frozen with what you have got.
"You are running with your hands tied behind your back.
"It is competition, like it is on the chassis side. If you start on the back foot then you can develop your way out of that."