Thursday 5 June at 17:51 : Robert Kubica is not a genuine challenger for the 2008 title, despite lying just six points behind Lewis Hamilton's championship lead.

That is the insistence of the impressive 23-year-old Pole's team boss Mario Theissen, who said BMW-Sauber is staying firm on its pre-season objective of winning its first race.

When asked by the German news agency SID if Kubica can stay in with a shout of the drivers' crown throughout the season, Theissen replied: "That would be unrealistic.

"We have an ambitious timetable: we want to win our first race this year, and then starting from 2009 be fighting for the title.

"Since we took over Sauber, we achieved the goals we set for ourselves and we want to keep making one step after the other," he added.

Theissen also backed Kubica's teammate, Nick Heidfeld, to emerge from his current performance trough, thought to have been traced to the 31-year-old's difficulty in getting heat into the 2008 car's tyres.

"We have to do everything we can so that he can get out of this low as quickly as possible," the German said.

"We know what he can do, especially when he is under pressure -- in these situations he can deal with it and be at his best."