The device, which channels away exhaust gases so removing wake from the rear wheels as well as creating more downforce and performance, has propelled Red Bull to eight poles in nine grands prix this year.

McLaren had planned to introduce their design for the German Grand Prix at Hockenheim in a fortnight, but were eager to give themselves more of a winning chance at Silverstone this weekend.

However, yesterday’s two practice sessions in front of a record-equalling Friday crowd for the British Grand Prix of 85,000, did not go according to plan.

Lewis Hamilton and Jenson Button could only manage eighth and 13th quickest, with the latter in particular admitting to difficulties in trying to find the correct balance.

The team have now returned to the old design of their car which may propel them closer to the front, but undoubtedly gives Red Bull the clear advantage in today’s qualifying and for tomorrow’s race.

McLaren engineers and test driver Gary Paffett have worked through the night in order to make the changes, with the first test coming in the final hour-long practice session.