F1 Supremo Bernie Ecclestone has told Sky Sports that Mercedes Non-Executive Chairman Niki Lauda had shook hands with Red Bull owner Dietrich Mateschitz on an agreement to supply the Four Time World Champions with a Mercedes Engine for 2016.
"I thought and was told that Mr Lauda had made an agreement with Mr Mateschitz and they had a nice handshake when Niki confirmed they would be supplied with Mercedes engines"
However, the deal appears to be dead in the water as Red Bull's only option right now is to be supplied with a Ferrari Engine. Which then asks the question of, what happened to the agreement with Mercedes? The answer to that is currently unknown, but Red Bull were formally rejected by Mercedes after the British GP other than that, there is nothing concrete to report between the two parties.
Bahrain International Circuit - Winter testing