In an interview with F1.com, Wolff said: "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.

"Therefore we decided 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."

Mercedes' refusal has left Red Bull with a choice of either seeking an engine deal with Ferrari for 2016 or opting to quit the sport altogether, something it has threatened if it is not given performance parity with the Ferrari works team.

But while the latter situation could see the grid shrink by four cars, with Toro Rosso also poised to pull out of the sport in the event of the energy drink giant not getting its way, Wolff is adamant Mercedes is in the right in turning Red Bull down.

"I have never hidden my opinion," he said. "It is the opinion of somebody who is responsible for the Mercedes motorsport program, responsible for 1,200 employees and who also has the responsibility to represent the Mercedes-Benz brand in the right way in Formula One‎ - and to make sure it is represented in the right way by others, too."

Customers treated equally

Williams driver Felipe Massa admitted last weekend in Singapore of being unsure if his team would receive the latest specification of Mercedes engine, which was trialled for the first time at Monza, but Wolff insisted that this would eventually be the case.

"We have the philosophy of supplying the same specification of engines to all," clarified the Austrian.

"There might be exceptional situations, like the one in Monza recently, where we carry out development work that needs to be checked on track - and therefore the supply of parts is very difficult."

Referring to the failure that prevented Nico Rosberg from finishing at the Italian track, he added: "I am not sure if our customers would have been happy with a car stopping because they ran a development engine!"