Mercedes Formula One boss Toto Wolff blasted rivals on Monday for casting doubt on the legality of his team's new engine through secret meetings and letters.
The sport is entering a new era with one of the most sweeping technical overhauls in decades and there has been talk of Mercedes and rivals Red Bull, now making their own engine, exploiting a loophole in the rules through the thermal expansion of components.
That could put the three Ferrari-powered teams (Ferrari, Cadillac and Haas), Audi and Aston Martin (Honda) at a competitive disadvantage if true.
Mercedes provide engines to four teams, while Red Bull also supply Racing Bulls.
"I just don't understand that some teams concentrate more on the others and keep arguing a case that is very clear and transparent," Wolff told reporters ahead of the team's online season launch.
"Communication with the FIA was very positive all along. And it's not only on compression ratio, but on other things too," added the Austrian.
"It's very clear what the regulations say. It's very clear what the standard procedures are on any motors, even outside of F1."
Wolff said rivals needed to get their act together instead of "doing secret meetings and sending secret letters and keep trying to invent ways of testing that just don't exist."
"Maybe you want to find excuses before you even start it (the season), why things are not good... it's not how we would do things," he added.
"Especially not after you've been told a few times that that is fine, it's legal and it's what the regulations say. But again, if somebody wants to entertain themselves by distraction then everybody's free to do this."
Formula One's governing body has played down talk of the controversy triggering a protest that overshadows the Australian season-opener on March 8.
Mercedes started the last engine era in 2014 with a dominant power unit and racked up a record eight constructors' titles in succession.
Wolff said the early evidence from an initial shakedown involving 10 of the 11 teams was that there was less of a gap than feared by some.
"In terms of pure performance on a lap, and even over several laps, it's looked like there is no-one that is really collapsing," he said.