"Shocked" Sebastien Bourdais is considering taking legal action after being dumped by Toro Rosso.

Team boss Franz Tost confirmed earlier on Thursday the team had released Bourdais as the partnership had "not met our expectations."

The 30-year-old certainly disappointed during his 18 months with the Italian-based team, winning a mere six points from 27 grands prix.

Last year the Frenchman found himself overshadowed by Sebastian Vettel, and despite being given a second chance this season, has struggled against 20-year-old Swiss rookie Sebastien Buemi.

Bourdais, though, considers the team have breached the terms of his contract, and is now looking at taking the matter further.

"I am very disappointed and shocked by the decision taken by Toro Rosso of not allowing me to drive for the team until the end of the current season," remarked Bourdais.

"I consider that in doing so, Toro Rosso has breached its contractual duties towards me.

"I also believe nothing in my behaviour would legitimate a decision of the team to terminate the contract.

"I think the team's decision is in clear violation of Toro Rosso's obligations under the agreement.

"I have instructed my lawyers to review the situation, including the possibility of issuing legal proceedings."

Bourdais felt with the team to introduce a considerable upgrade at the next grand prix in Hungary next week that he deserved a chance to prove himself with the new car.

"I am even more frustrated by the team's decision considering it has been taken immediately before the Hungarian Grand Prix where a new, highly competitive racing package will be introduced in order to try and overcome current difficulties," added Bourdais.

"I am convinced if I was given the chance to race with such a new package I would have had the opportunity to achieve satisfactory results."

Bourdais insists his "motivation is intact" and that he remains committed to Formula One, but it is almost certain rising Spanish star Jaime Jaime Alguersuari will be in the car in Budapest.

The reigning British F3 champion, a product of Red Bull's Young Driver Development programme, is due to become the youngest to race in F1.

Alguersuari would take his place in the record books at the age of 19 years and 126 days, beating New Zealander Mike Thackwell's record by 57 days set in the 1980 Canadian Grand Prix.