Brawn's Rubens Barrichello top after opening free practice at European GP

Brazilian veteran Rubens Barrichello topped the times for Brawn GP after the opening free practice session for this weekend's European Grand Prix.

The 37-year-old Barrichello clocked a best time of one minute and 42.460 seconds around the Mediterranean harbour street circuit with 15 minutes remaining on a hot morning in eastern Spain.

Finn Heikki Kovalainen was second fastest for McLaren ahead of his team-mate, defending drivers world champion Lewis Hamilton of Britain, who won his first race of the season at last month's Hungarian Grand Prix.

Championship-leading Briton Jenson Button was fourth in the second Brawn at the conclusion of an eventful morning's action which ended with Barrichello's car struggling with gearbox problems as he went for an even faster lap time.

Button was fastest for a long period during the morning, but ended up six-tenths of a second off Barrichello's pace, but the duo's overall performance suggested that Brawn have rediscovered some of their best form after three races in the doldrums.

German Sebastian Vettel was the top Red Bull driver in fifth position ahead of compatriot Adrian Sutil, who was sixth for the much-improved Force India team.

Japanese Kaazuki Nakajima was seventh for Williams ahead of Australian Mark Webber in the second Red Bull with two-times champion Spaniard Fernando Alonso of Renault and Finn Kimi Raikkonen of Ferrari completing the top ten.

The session saw a flurry of incidents, but no serious accidents, as many drivers ran wide over the kerbs on the dusty asphalt circuit.

French debutant Romain Grosjean of Renault was 17th, more than a second slower than team-mate Alonso and veteran comeback driver Italian Luca Badoer, replacing injured Brazilian Felipe Massa for Ferrari, was 20th, two seconds down on Raikkonen.

Williams blocks Michael Schumacher's Plans to Test Car Ahead of F1 Return

Michael Schumacher's bid to step up his comeback by testing Ferrari's current car has been blocked by Formula One rivals Williams.

Ferrari last week wrote to the other nine Formula One teams and the FIA requesting Schumacher be granted a day at the wheel of the F60 ahead of the German legend's return to racing at the European Grand Prix in Valencia on August 23.

Under current regulations in-season testing is banned, but Schumacher hasn't raced since his retirement in 2006, so Ferrari were hoping the seven-time world champion, who is standing in for Felipe Massa after the Brazilian's horrific crash in Hungary, would be allowed to practise.

Out of courtesy, the other seven members of the Formula One Teams' Association – McLaren, Renault, Toyota, BMW Sauber, Brawn GP, Red Bull Racing and Toro Rosso – gave Schumacher and Ferrari the green light.

Williams, however, see no reason why Schumacher should be given special dispensation, citing the recent arrival of 19-year-old rookie Jaime Alguersuari into F1.

"While we welcome Michael Schumacher back to Formula One, the fact is 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," said Williams in a statement.

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

"Williams sees no distinction between Alguersuari's situation and Schumacher's and feels any deviation from the rule would create a precedent for the future.

"For the sake of consistency and fairness, therefore, we oppose Ferrari's proposal to test ahead of the European Grand Prix."