WILLIAMS, Red Bull Racing and Scuderia Toro Rosso have blocked Ferrari’s attempts to secure Michael Schumacher a testing exemption ahead of his much anticipated Formula 1 return at Valencia.

The Scuderia were keen to get the German up to speed behind the wheel of F60, and adapt to the changes to the 2009 machines, including the Kinetic Energy Recovery System and movable front wings.

However, the trio have denied Ferrari’s request, claiming there is little difference between the cases of Schumacher and Spanish teenager Jaime Alguersuari, who made his debut at Hungary despite never completing a lap in a Formula 1 car.

Red Bull owner Dietrich Mateschtz said a similar request to allow Alguersuari to test the Toro Rosso was denied by the teams after he was selected to replace Sebastien Bourdais.

“We asked for a test permission for Alguersuari before the Hungarian GP and it was turned down. So why should we approve an exemption for a seven-time-champion after this?” he told Autosport.

“We are happy that Jaime did such an excellent job on his debut.”

Williams F1 boss Frank Williams meanwhile said his company’s decision to reject Ferrari’s request was based on the notion teams should call-up their test drivers if one of their regular pilots is unable to compete.

Williams also believes the situation could create a precedent for future requests, and ultimately force teams to comply.

“While we welcome Michael Schumacher back to Formula 1, the fact is that any form of in-season circuit testing is strictly prohibited; a regulation clearly laid out by the FIA and adhered to by all of the teams,” he said.

“It was for this reason that Alguersuari, who drove an F1 car for the very first time in Hungary, did not have the opportunity to familiarise himself with the Toro Rosso before he made his race debut.

“In a similar situation, Williams would unhesitatingly use its current test driver. For the sake of consistency and fairness, therefore, we oppose Ferrari’s proposal to test ahead of the European Grand Prix.”