The tingle of anticipation at the start of a new grand-prix season was tempered here yesterday by mounting concern that the outcome of the first round of the world championship could be decided in the scrutineering bay long after the chequered flag has fallen tomorrow afternoon.

As the drivers grappled with spectacularly reduced levels of grip - the result of new technical regulations - during yesterday's intermittently wet preliminary practice session, so pressure mounted for the governing body (FIA) to ban the McLaren-Mercedes MP4/13s that are expected to emerge as the early-season pace-setters.

The McLaren system, which allows the drivers to apply extra braking effort to the inside rear wheel for improved traction and stability during cornering, was first used by the team last season. It has been further developed over the winter, during which time McLaren were in regular touch with the FIA to ensure it conformed with the rules.

"We have consulted them on all aspects of its specification," said Ron Dennis, McLaren's managing director. "The governing body is satisfied about its legality in every respect."

Before practice, however, the Ferrari technical director, Ross Brawn, sent a memorandum to the FIA's technical delegate, Charlie Whiting, claiming that the braking system did not, in his view, conform to the regulations. Ferrari sent copies to all the other competing teams.

Yesterday morning Whiting had told the teams he was satisfied that the system conformed to the regulations, but added that, if they were not satisfied with his opinion, they could use their right to lodge a protest after the race.

Ferrari then tried to get the teams to countersign a letter objecting to the McLaren system. At least five agreed to do so.

Whichever way the issue is resolved, many team owners blame the Formula One technical regulations as being insufficiently specific. And, in terms of public relations, the last thing F1 wants at this stage is another wrangle.

Practice times in Sports Round-Up