McLaren puts in huge late-night effort

The Woking-based outfit had high hopes that the development package it fast-tracked for introduction at Silverstone would give it enough of a speed boost to overhaul title rival Red Bull Racing.

However, problems with the handling of the revamped car - which sources suggest was caused by heat from the exhausts warping the floor of the MP4-25 and affecting its aerodynamics - made the team rethink its strategy and remove the diffuser on Friday night.

The team has, however, kept the new front wing that it introduced - and it flew test driver Paffett back to its Woking factory for an extensive run in the simulator to work on set-ups for the latest combination of parts on Friday evening.

Although the removal of the exhaust-blown diffuser is a blow to McLaren's hopes this weekend, the team is far from despondent about its plight.

Engineering director Paddy Lowe told the BBC that he remained upbeat that the outfit could still be strong.

"We were competitive in Turkey without the blown diffuser, and that's a similar sort of track to here," he said. "The blown diffuser is an influence in terms of performance around here but we've got other new parts on the car that we're very happy with so we're reasonably optimistic."

McLaren is hoping that it can revamp the exhaust-blown diffuser in time for it to return at the German Grand Prix in a fortnight's time.