A war of words between Renault boss Flavio Briatore and Nelson Piquet has increased speculation that the Brazilian driver is unlikely to finish the season with the team.
Piquet admitted ahead of the Hungarian Grand Prix that his place at the team was in doubt, with rumours having already suggested he could have been absent from the Hungaroring race, where the Brazilian qualified in 15th and finished in 12th.
Speaking to Autosprint magazine, Briatore said he expected more from Piquet and was critical of the driver for "opening the book of excuses" for his lack of results.
"I've always been fair with my drivers," Briatore was quoted as saying by Autosprint. "I expected more from Piquet because this is his second year with a full-time drive. He's done less testing compared to Alonso, but Webber as well tested less than Vettel because of his broken leg, but look where he is now.
"When a driver lacks results, he opens the book of excuses and begins: the fault is the weather's, a spectator's sunglasses, a spin on the straight, this and that...
"It's not true that there's a technical difference of seven tenths between Alonso's and Piquet's car. If that was true, we'd have a car capable of winning the title, and that unfortunately isn't the case. The technical difference has always been minimal and never longer than one race."
Piquet, who is yet to score a point this season, was critical of his team boss, saying he only thinks about money.
The Brazilian driver claimed Briatore, who left Sunday's race before it was over after Fernando Alonso had retired, has no respect for him.
"Flavio is a business man, but he doesn't understand s*** about F1," Piquet was quoted as saying by the Italian magazine. "He's my manager, but in his role of team boss he doesn't respect me.
"He only thinks about money, at how much money he can pocket in everything he's involved, he's a man with no friends. Every day everyone asks me what's going on, so why should I always keep quiet?
"Webber has been in F1 since 2001, he started in a different era, when testing wasn't limited. He's probably done more than 20,000 kms in testing, so it's not a fair comparison. Now the situation is more difficult for a driver with little experience.
"And besides that, I have to fight against Briatore and Alonso himself, who is a fantastic driver. When I wasn't competitive in qualifying, I was the first to own up to it. But if Briatore doesn't understand that, what can I do?"