Toto Wolff has quashed fears that McLaren's decision to swap to Honda power in 2015 will hurt their chances next season.
2014 will definitely be McLaren's final year with Mercedes engines as the Woking team has opted to return to Honda with whom they had success in the past.
There are concerns that McLaren could suffer as a result as Mercedes become wary of sharing their V6 secrets with their soon-to-be departing client.
Wolff, though, insists McLaren will get equal treatment.
"McLaren is a customer and we have long history with McLaren, so we will do everything to support them from Mercedes' point of view," he said.
"We are in modern times so there is no such thing as different specs [of engine] and different specs are not allowed by the regulations anyway. The support of Mercedes is there [for McLaren] as it is for anybody else."
Meanwhile, McLaren's managing director Jonathan Neale concedes that Mercedes will be wary of sharing secrets but believes they will still provide the F1 team with the goods.
"I've worked with Mercedes for a long time and I know the team up there [in Brixworth]," he told ESPNF1.
"I think when you have limited engines - the days of six engines in a weekend are long gone - with just five power units for the year, it means that in order to get a high-quality part, everything coming down the production line has to be the same. They can't have an 'A' model, a 'B' model and a 'C' model.
"Now, do I think in a glimmer of a dyno somewhere that the one that's a little bit better might go in one direction? I think so, but it's going to be in the noise. Parity is something that will give Mercedes-Benz the quality and brand reputation that they want, so I don't fear that at all.
"In terms of the service that we are getting, then clearly they are not going to reveal as much of the internal workings of what is going on. But I've no worries about the quality of team we have in the garage or the support from Brixworth."