Piquet Jr has continually struggled to impress in Formula 1 for Renault
Nelson Piquet Jr has been told by Renault he will not continue driving for them in Formula 1 this season.
The 23-year-old has had 28 races in F1 without recording a win and has not won a point in his 10 races this season.
"I have received notice from Renault of its intention to stop me from driving for them in the current F1 season," read a statement on his website.
Piquet described this season as "the worst period of my career" and has criticised team boss Flavio Briatore.
"I believe without doubt in my talent and my performance," said the Brazilian, who finished second to current F1 world champion Lewis Hamilton in the 2006 GP2 championship.
A manager is supposed to encourage you, support you, and provide you with opportunities... Flavio Briatore was my executioner
"I didn't get this far by getting bad results. Anyone who knows my history knows the results I am having in F1 do not match my CV and my ability.
"The conditions I have had to deal with during the last two years have been very strange to say the least - there are incidents that I can hardly believe occurred myself.
"If I now need to give explanations, I am certain it is because of the unfair situation I have been in in the past two years.
"I always believed that having a manager was being a part of a team and having a partner.
"A manager is supposed to encourage you, support you, and provide you with opportunities. In my case it was the opposite - Flavio Briatore was my executioner."
He added: "I am a team player and there are dozens of people I have worked with in my career who would vouch for my character and talent, except unfortunately the person that has had the most influence on my career in F1."
Piquet also accused the Italian of behaving unfairly towards him during his time driving alongside two-time world champion Fernando Alonso.
"On numerous occasions, 15 minutes before qualifying and races, my manager and team boss would threaten me, telling me if I didn't get a good result, he had another driver ready to put in my place."
Piquet Jr - whose father Nelson Piquet was F1 world champion in 1981, 1983 and 1987 - vowed to remain in motorsport but did not specify whether he would stay racing within F1.
"I feel a sense of relief for the end of the worst period of my career, and the possibility that I can now move on and put my career back on the right track and try to recover my reputation of a fast, winning driver," he said.
Piquet Jr's replacement is unknown as yet though Renault test driver Romain Grosjean is expected to be in contention.