David Coulthard has expressed his fears over his former outfit Williams' promotion of Kazuki Nakajima from the role of test-driver into the race team in 2008, arguing the Japanese rookie is not ready for the top flight just yet.

Twelve months on from his suggestion that Lewis Hamilton should not be thrust into Formula 1 before he was fully-prepared, the Scot has accused Nakajima of dangerous driving following the pair's collision towards the end of last month's Brazilian Grand Prix - the GP2 graduate's debut in the uppermost echelon - and underlined 'F1 is not a finishing school'.

"He passed me on the outside into turn one, which was fair enough," Red Bull Racing star Coulthard wrote in his regular column for ITV, "but there was no need for him to cut across the front of me afterwards.

"In fact we agree in drivers' briefings not to move across the front of somebody during braking because cars get airborne that way."

Both would go on to finish the race - with the RBR taking the chequered flag ahead of the Williams, just outside the points - but while Coulthard reported damaged suspension, Nakajima insisted he had done nothing wrong. The 22-year-old's race was initially memorable for having run over a member of his pit-stop crew when he came in to refuel for the first time.

Coulthard - who drove for Williams himself in 1994/95, and who with 229 grand prix starts under his belt is now the second-most experienced driver in the field - was nevertheless keen to stress his remarks were not a case of sour grapes.

"I'm conscious that my words will be seen as the racing old boy getting overtaken by the new guy," he added, "but this sort of thing tends to happen less between more experienced drivers.

"Driving standards in GP2 are generally pretty wild, but there should be a higher standard that some of these rookie drivers need to meet before they are allowed to race in F1.My team-mate Mark Webber said recently 'F1 is not a finishing school', and I totally agree."