LONDON • Further sustained dominance by Mercedes would be "unpalatable" for Formula One (F1), according to Red Bull principal Christian Horner.
The 43-year-old Englishman also believes the sport's new owners, Liberty Media, would surely have to act if the world champions prove yet again to be far ahead of the rest of the field under the new regulations which are set in place for the next three seasons.
But Ross Brawn, Liberty's new motor sports director, has made it clear that no artificial curbs would be imposed on any F1 team because of their success.
Mercedes have won the last three drivers' and constructors' championships, with their closest rivals Red Bull and Ferrari unable to mount a sustained challenge.
Horner - whose Red Bull team have won only five races in three years after reigning supreme from 2010 to 2013 - believes F1 is in desperate need of competitive racing.
"It's unpalatable to think of it for another three years," he said. "The new owners of F1 know very much about putting on a great show and there being good and healthy competition.
"That can't be artificially done obviously but I would be surprised if they were prepared to allow total dominance like the last three years."
Mercedes dominating again, he added, "would be bad for the sport. But how you prevent it from happening I don't know. It would be wrong to artificially slow someone down. We have just got to work hard to put them under pressure."
Brawn, who is working to develop F1's regulations to aid better racing, agrees with Horner on this. "If you start applying penalties, well that's not Formula One," he said.
"The difficulty is that you end up having artificial constraints to try and correct it which the fans don't like. Fans will see through an artificial solution."
Brawn is more inclined to look for a solution in addressing the disparity between teams' income, with the sport's governing body, the International Automobile Federation (FIA), having a role.
He said: "The real core of it is to look at how you level the playing field in terms of financial resources and so forth, and that's why the five-year plan must include the funding of the teams.
"Budget control and distribution of funds is a pretty major issue. These are tough debates we are going to have to have with the teams and the FIA to see what progress we can make.
"There is a disparity of funds in F1. You can legitimately argue that Ferrari and Mercedes are a bigger draw to the show but how do you proportion it, to make a fair distribution of funds?"
Ferrari were quickest in pre-season testing but Mercedes were strong on reliability and are expected to have more pace come the first race of the season in Melbourne on Sunday.