S?bastien Bourdais has revealed his shock, disappointment and frustration in Scuderia Toro Rosso for having released him midway through the 2009 F1 World Championship campaign - threatening to initiate legal action against the Red Bull 'junior' concern for what he believes to be a breach of contract and vowing to remain firmly committed to a future in the top flight.

It was confirmed by the team earlier today that the record-breaking former multiple Champ Car king will no longer be in the cockpit of the #11 machine come the Hungarian Grand Prix in Budapest in just over a week's time - when a raft of updates will be introduced to the unloved and hitherto underperforming STR4, designed to vault it some way up the starting grid.

Bourdais has struggled to get to grips with the car over the first half of the season, leaving him to be shown up by young rookie team-mate and namesake S?bastien Buemi. A similar upgrade last year helped to transform the Frenchman from a tail-ender into a regular points challenger - and he contends that not granting him the chance to prove his mettle with the new evolution this time around is cruel indeed.

"I am very disappointed and shocked by the decision taken by Scuderia Toro Rosso of not allowing me to drive for the team until the end of the current season," the 30-year-old said in an official statement. "I consider that, in doing so, Scuderia Toro Rosso has breached its contractual duties towards me; also I believe that nothing in my behaviour would legitimate a decision of the team to terminate the contract.

"I think that the team's decision is in clear violation of Scuderia Toro Rosso's obligations under the agreement. I have instructed my lawyers to review the situation, including the possibility of issuing legal proceedings.

"I am even more frustrated by the team's decision considering that it has been taken immediately before the Hungarian Grand Prix, where a new, highly-competitive racing package will be introduced by the team in order to try and overcome its current difficulties. I am convinced that if I had been given the chance to race with such a new package, I would have had the opportunity to achieve satisfactory results."

The driver expected to benefit from that opportunity, by contrast, is reigning British F3 Champion and current RBR and STR reserve driver Jaime Alguersuari, but if some are tipping Bourdais to return across the Pond in a bid to resurrect his career in America once again, the man himself is adamant that they could not be further from the truth.

"My motivation is intact," he concluded, making a point of thanking his fans for their ongoing support, "and I will continue to be strongly committed to my Formula 1 project, for which I have renounced my career in the United States."