Nico Rosberg has hit back at Niki Lauda after the Mercedes boss accused him of making the team look dumb with his shock retirement.
Lauda earlier this week accused Rosberg of leaving Mercedes in the lurch by retiring just days after winning the Formula 1 world championship.
"What annoys me the most is that now Nico is telling us that he would have continued had he not won the world championship," Lauda was quoted as saying in Germany's Die Welt newspaper.
"This is something he could have at least hinted at when he signed his contract. In this case, we could have prepared a Plan B — we would have had to in order to be ready. But it is as it is.
"We all gave him the opportunity to become world champion in a fantastic car — and then he tells us he wants to retire.
"This has created a huge hole in this great working team. And we're left looking dumb."
Rosberg has since responded in a Q&A with fans on Facebook — and gave the F1 legend, who won three world championships during his racing career, a brutal history lesson.
"Well the entire time I was talking a lot to Niki and (he was) completely different from the way he acts in the media," said Rosberg, in German. "I think that is because of his disappointment, which I can understand. It's what made this decision the hardest for me because I know that I brought hard times upon my racing family.
"I knew that would happen, that was the hardest part and that is exactly why one hour after I decided to retire I told (Mercedes boss) Toto Wolff, to give them as much time as possible to find an alternative.
"But to say I deserted the team? Well, not really. I can't only drive because of the team.
"And on top of that — Niki quit during a race weekend in 1979 in the middle of the season and he was younger than me. Maybe he forgot about that."