Flying in the face of the opinions expressed by both Ferrari and BMW over the past week, Ross Brawn has thrown his support behind the FIA's new optional ?40 million budget cap in Formula 1, warning that without it the top flight risks 'turning [engineers] into Swiss watchmakers' - but equally underlining that it will only be workable if it is embraced by all.

Brawn's former boss, Ferrari President Luca di Montezemolo, has blasted the initiative as being 'fundamentally unfair and perhaps even biased', with BMW Motorsport Director Dr Mario Theissen urging that 'a two-class Formula 1 is not attractive to BMW', since 'in one go you cannot just evaporate by a factor of three'.

Whilst stating the case for the cap in times of such global economic turmoil and following years of escalating expenditure in the world's most expensive sport, Brawn fervently agrees that a two-tier system of haves and have-nots - with some competitors adhering to the cap and benefitting from its greater technical freedoms, and others continuing to race on an unlimited budget but with more restrictions in place - is not the way to go.

"We don't want to see a two-tier Formula 1," he contended. "We think that would confuse the public, [and] if there is a big disparity in the regulations there will be no merit for those teams that succeed using the most advantageous regulations.

"It's a fact that stability - when the rules are right - is the cheapest way of going forward in many ways, because you can plan [and] you can organise yourself, but one of the difficulties of Formula 1 is that we're turning into Swiss watchmakers. We're just refining everything to the nth degree instead of being able to make conceptual changes or innovative changes because the rules are becoming more and more restrictive. In order to try and contain the costs, we're just closing everything down so much that I'm not sure that's what Formula 1 should be.

"We, as a team - both in Honda days and now - support the idea of a constraint on resources of some sort, be it financial, be it people, be it some constraint where everything is enclosed and within that enclosure there is more freedom because most of the technical changes we're doing are to save cost. If we can save cost by saying 'that's all you're allowed to spend' and have more freedom, for me that's a more exciting Formula 1 [and] we've always supported that concept."

The Formula One Teams Association (FOTA) - of whose technical committee Brawn is the chairman - has demanded 'urgent' talks with the governing body regarding the cap, and with its scheduled introduction in 2010, the Englishman is well aware that time is short.

"I think all the teams within FOTA don't want to have a two-tier system," he acknowledged, "and I think there will be discussions over the next week or so. As soon as it's possible, we would like to meet with Max [Mosley - FIA President] and try and find if there's another way forward, where all the teams can be united and consistent in the solution.

"What we want to do as a team is find a solution to that with all the other teams. We don't want difficulties in Formula 1; we want to work with the FIA, we want to work with all the teams and find a solution that fits with that. For us, there has to be some constraint on resources - not a constraint on the technical regulations."

Turning his attentions to the action on-track, this weekend's Spanish Grand Prix in Barcelona has been billed as the true acid test of who really stands where in the 2009 F1 pecking order. Brawn GP has dominated the initial stage of proceedings with three victories for Jenson Button from the opening four 'flyaway' races of the campaign, and a comfortable 22.5-point margin over closest pursuers Red Bull Racing in the constructors' title chase.

Whilst the traditional 'grandees' like McLaren-Mercedes, Ferrari, BMW-Sauber and Renault have all brought along a raft of modifications to the Circuit de Catalunya for the start of the European leg of the season, with a new floor, new engine cover and new bodywork around the rear suspension of its Mercedes-powered BGP 001 challenger, the ex-Honda F1 outfit has been far from standing still either.

Its team principal also made a point of defending the performance of veteran Rubens Barrichello so far this year, with the Brazilian having largely struggled to keep pace with team-mate Button - particularly on race day - and having stood up on the rostrum just once, when the British star has never been off it.

"It is always very difficult to even maintain your position wherever it is in Formula 1," Brawn contended, "as it moves forward so quickly. The big challenge we all have is that with no testing you are effectively on a [grand prix] Friday trying to work out what you have got and where you are. It is not such a straightforward process as it used to be. Testing itself was always very difficult anyway, but it is extremely difficult now.

"We have brought a new package here which seems to be working very well with Rubens, but we have got a problem with it with Jenson and we have to understand what is going on. It is quite a difficult year for everybody, and it will continue to be difficult with the testing rules that we have.

"We have a reasonable-sized team now and we are not budget-limited in what we can do; we are just being careful in how we spend that money - perhaps we bring three or four sets of parts to a race whereas last year we might have brought six or seven. We make those sorts of judgement calls, but we are certainly not holding back on doing any performance improvements that we can. There is a package here, there are some modifications for Monaco and there is another update for the N?rburgring, so we are working hard.

"I think Rubens has had a little bit of bad luck. I know luck shouldn't come into it, but I think in China he was looking very strong - in fact probably for a dry race he was in better shape than Jenson - but then in the wet he had a problem with the brakes; one of the brakes glazed over on the rear, which made life very interesting for him.

"In the last race, in Bahrain, the front wing adjustor failed and the front wing flap dropped down as he was in the middle of his qualifying lap. We'd gone for a pretty aggressive strategy and that meant being at the front, and he didn't achieve it because we had a problem with the car.

"I'm pleased with Rubens' performance this year. He's contributed an awful lot to the team, helping to sort the car out. He gives very valuable technical information, and I think it just hasn't quite fallen for him this season. Jenson's doing a superb job, so that's the reference, but I'm very happy with Rubens' performance and I'm sure that if we get a smooth weekend he'll be up there."