Norbert Haug has moved to again re-affirm Mercedes-Benz's commitment to Formula 1 - despite admitting that 'it might take a few races' for McLaren-Mercedes' ill-handling new contender 'to significantly improve' in 2009.

The MP4-24 - expected to be the machine with which the Woking-based outfit fought to successfully defend Lewis Hamilton's drivers' crown from last year and regain the constructors' laurels to boot - has endured a troublesome birth in testing, languishing repeatedly towards or even at the bottom of the timesheets at Jerez and Barcelona in the hands of Hamilton, team-mate Heikki Kovalainen and Pedro de la Rosa.

It is understood that that the team is struggling most notably on the aerodynamic front, with the diffuser and rear wing believed to be the weakest links. For much of the winter, indeed, the Woking-based outfit has run with the 2008-spec rear wing whilst its rivals have developed the 2009 package.

With precious little testing time now remaining ahead of the curtain-raising Australian Grand Prix in Melbourne in less than two weeks' time, Mercedes-Benz Motorsport Vice-President Haug has confessed that it could take several grands prix before the squad is ready to challenge for glory.

"We are definitely not where we want to be," the German is quoted as having conceded by Formula1.net. "We will continue our test programme at Jerez for another four days - but it might take us a few races to significantly improve. We still have a lot of work ahead of us to improve the technical package.

"Obviously, there is a lack of downforce and we are currently working hard to solve this problem. Basically, the car feels good - that is what our drivers say. However, we are currently definitely not fast enough, nor competitive enough to aim for victories. Our performance is not yet where it should be, but we will work very hard to improve it and get back to our standards."

Even more embarrassingly still for the multiple world champions is the fact that Brawn GP and Force India - both of which are supplied with Mercedes-Benz customer engines - have proven to be substantially quicker than McLaren in testing so far. Whilst acknowledging that Brawn GP 'has done a remarkable job' and is rapid over both a single lap and also a race distance, Haug is adamant that there is no cause for concern about the Stuttgart manufacturer's partnership with McLaren or future in the top flight, global credit crunch or no.

"The Mercedes-Benz Formula 1 programme is a long-term commitment," the 56-year-old stressed, quoted by Planet-F1. "With Lewis Hamilton we won the world championship last year. Our partnership has won three drivers' titles and one constructors' title so far, and we will be back fighting for more championships even if it takes some time this year.

"We have demonstrated in the past that we can win against the strongest opposition, and we will work very hard to prove this again."

Recently-promoted McLaren team principal Martin Whitmarsh broadly echoed Haug's sentiments, recognising the MP4-24's 'performance shortfall' in relation to 'the team's extremely high standards'. Whilst agreeing with his Mercedes counterpart that the two parties are 'in it together', the Englishman was also frank about where the fault lies.

"Our Mercedes-Benz engine is strong - we saw that last year - so the MP4-24's performance shortfall is clearly chassis-centric," the 50-year-old stated. "Inevitably, in 21st-century Formula 1, it is a car's aero aspect that confers the greatest pluses and minuses to its overall performance package, and that would appear to be the case with the MP4-24 - but Formula 1 engineers can do great things when the pressure is on.

"We are working hard and are testing at Jerez, which many of our rivals are not. We aim to continue to develop the car, and the result should be measurable on the stopwatch. Will the MP4-24 be as quick as we want it to be by 29 March? Perhaps not. Will it be quicker than it has been at the Barcelona test? Yes."

That confidence backs up remarks made by Whitmarsh's predecessor and McLaren Group chairman Ron Dennis, who recognised that the 'production challenges' had been largely caused by the team's deliberate tactic of leaving the development of its aerodynamic package until the last possible moment in the light of the sport's dramatic new regulations in 2009.

"We really only started to run the car in the last day with the Australian aero package," the 61-year-old reasoned. "We ran the 2008 rear wing because it was more relevant in its performance to the wing that we are going to have in Australia.

"It doesn't mean you are lost or that you don't know what you are doing. Whereas our main competitors have finished testing, we still have the ability to test in Jerez. When we get to Australia that will be the first measurement of everyone's performance.

"We expect our car to go faster with every grand prix and we expect to maintain our pace to allow us to win the world championship."