A three day test at Jerez de la Frontera got underway today in controversial circumstances, as cracks in the testing agreement between the nine 'rebel' teams began to show.

As previously reported on Pitpass, with eight rounds of the 2005 Formula One World Championship remaining, some teams are already perilously close to reaching the thirty-day test limit. However, today, Toyota opted to run three cars, another cornerstone of the agreement between the nine.

Nonetheless, Ralf Schumacher put the politics to one side as he set the fastest time of the session, despite an incident earlier in the day which saw him 'up close and personal' with the tyre barriers. The German, who completed 57 laps, finished 0.100s ahead of BAR's Jenson Button.

Jenson spent his early running in chassis 06, finding a good balance in preparation for his planned aero test. He completed 54 laps in the morning session, while Anthony Davidson ran through a suspension evaluation.

The afternoon proved frustrating for both drivers with a total of six 'red lights' causing frequent interruptions to the session. Jenson ran through a further aero evaluation, setting the second fastest time of the day.

Renault endured a troubled opening day, at the start of the final full test before the summer ban.

Both drivers experienced delays to their programme that prevented them running as much as initially planned. Nevertheless, Franck Montagny made progress with the tyre programmes for upcoming races, while Giancarlo Fisichella conducted set-up and suspension work before a problem with the braking system ended his day.

"It was a slightly frustrating day with various delays to both cars' programmes," admitted Christian Silk. "We struggled to get a good balance on Franck's car, which delayed us before he could progress with the tyre performance work, while Giancarlo's day was cut short with a technical problem. In spite of the fact that neither driver was completely happy with the car, our times look competitive, but we will be hoping to achieve much more tomorrow."

Fourth quickest was Felipe Massa in the sole Sauber. "It was actually a tricky day today," revealed test engineer, Paul Russell. "There were quite a few red-flag periods in the afternoon, which made it a bit frustrating.

"However, our focus this week will naturally be the preparation for the next races whereby we will concentrate on high-downforce configurations. We have started to validate the new aerodynamic parts which were introduced in Silverstone last weekend and gathered good information. In addition, Felipe did some Michelin tyre work for Hockenheim and Budapest.

"For the rest of the week we have scheduled further aerodynamic follow-up work and to continue the Michelin tyre programme."

Red Bull had Christian Klien and Tonio Liuzzi on duty, in addition to finishing a respectable sixth and eighth, the duo was the most industrious, completing a total of 163 laps.

It was back to earth with a bump - or rather a bang - for Juan Pablo Montoya, whose engine detonated big time. Consequently, the British Grand Prix winner completed just 26 laps. To add to McLaren's misery, Alexander Wurz stopped out on track late in the session, having suffered an unspecified technical problem.

Juan Pablo's programme included Michelin tyre testing of the prime and option tyre for the forthcoming German Grand Prix, alongside suspension and aero development work. Alex was working on a tyre programme for the German Grand Prix, completing short runs in the morning and concentrating on heavy fuel loads and longer runs in the afternoon.

It was a bad day also for WilliamsF1, which had Antonio Pizzonia and Nico Rosberg on duty. In addition to running the two different spec FW27s - as used at Silverstone - the Grove outfit was due to run the new BMW V8.

However, stomach pains meant that the German driver withdrew from the test in the early afternoon, leaving his Brazilian teammate to do all the work.

"Nico spent the majority of today's test investigating the issues we are trying to resolve on the current chassis," admitted Tim Newton, WilliamsF1 test team manager. "He also completed some systems checks and set-up development work.

"Antonio drove the FW27B this morning, in which we are running the new BMW V8 engine for the first time, but returned to the FW27A chassis in the afternoon when Nico was forced to withdraw from the test with stomach problems. Antonio will be joined by Nick Heidfeld for the second day of the test."

Regular racer Mark Webber is already ruled out of the Jerez test as he is still recovering from burns to his hips received in France, which became inflamed - no pun intended - at Silverstone.

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