Obviously upset with the sport's revolutionary 2014 rules, team owner Dietrich Mateschitz recently hinted that his commitment to the sport has "a clear limit".
The wilder rumour is that Red Bull could switch to another racing category, perhaps with Cosworth engines.
"This is utter nonsense and unfounded," Marko, who is Mateschitz's motor racing right-hand man, told Germany's Auto Bild.
"As is Red Bull's philosophy, if you are in the top league, in this case motor sport, you do not go down a class. It doesn't make sense," he insisted.
Marko said any criticism of the 2014 rules is because Red Bull is alert to "negative trends".
"We have to watch and do everything to ensure that formula one keeps its reputation," he added.
Marko also rejected rumours the currently Renault-powered Red Bull is lobbying to be supplied industry-leading Mercedes engines.
"It would of course spoil it for them, if they (Mercedes) were to lose to us," he said. "They have built their factory team to win, so we do not expect Mercedes to supply us with engines."
He also played down reports Red Bull could design its own turbo V6.
"Basically, our main expertise is the chassis. So developing an engine would only be an option if we had no other alternative," Marko added.