Toto Wolff says Mercedes worked too long and hard to be successful in F1 to hand Red Bull an advantage by supplying them with engines.
Red Bull team principal Christian Horner revealed to Sky Sports F1 during the Singapore GP weekend that his team had approached Mercedes at the British GP about supplying them with engines.
The four-time world championship-winning outfit have blamed their lack of competitiveness since the start of the new hybrid era on Renault's power unit and were keen to switch to the Silver Arrows' engine considered the class leader.
"We decided with our board that we as an engine supplier - and as a team - have worked hard and long to achieve the success we have today, after taking the decision to enter the sport again as a works team in 2010," Toto Wolff told the official Formula 1 website.
"Therefore we decided two weeks ago against exploring an engine supply to Red Bull. We wish to continue with our model to support independent, privateer racing teams - and to respect the relationships we already have in place with our customers - alongside our primary focus on the Mercedes works team."
Put to Wolff that he was the driving force behind Mercedes rejecting Red Bull's approach, the Austrian hinted he had been and suggested that he didn't want to see the brand name tarnished by a partner the way Renault's has.
"I have never hidden my opinion. But we take decisions collectively and objectively, evaluating all the pros and cons, and not as individuals," he added.
"It is the opinion of somebody who is responsible for the Mercedes motorsport programme, responsible for 1,200 employees and who also has the responsibility to represent the Mercedes-Benz brand in the right way in Formula 1 - and to make sure it is represented in the right way by others, too. Full stop!"
With Mercedes rejecting Red Bull's approach the former champions admit their only option is Ferrari otherwise both they and Toro Rosso could leave F1.
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