Martin Whitmarsh has denied that McLaren has inserted a fresh veto against Red Bull's desire to be powered by Mercedes engines in 2011.
German reports this week said a deal between the currently Renault-powered team and Mercedes is possible for 2011, but Norbert Haug on Friday revealed that McLaren - still with an exclusive contract - has "put in the veto".
"Well, I've heard the rumours but that's it," McLaren team boss Whitmarsh said at Spa-Francorchamps.
He therefore denied that McLaren has vetoed a Red Bull/Mercedes deal, also hinting that he does not even have that power.
"I don't know of any plans, I haven't been consulted or asked and nor do I necessarily need to be," added Whitmarsh.
Mercedes GP team boss Ross Brawn also played down the reports.
"That's genuinely the first time I've heard the rumour. I don't think there are any plans for Mercedes-Benz to supply more teams," he said.
Also on Friday, technical boss Mike Gascoyne scotched the latest reports about Lotus switching to Renault power for 2011.
"We're using Cosworth engines and we've been very happy with their performance this year.
"I think as teams we always evaluate every option that's out there but at the moment we're very, very happy with Cosworth and the job they've been doing," said Gascoyne.