Romain Grosjean topped the times for Lotus in the opening practice session for the British Grand Prix at Silverstone, with heavy rain playing a part in proceedings throughout the 90 minutes of running.

Rain was falling when the session got underway and conditions failed to improve at all as the session wore on, with the rain getting heavier after Grosjean had posted the time that would prove to be the benchmark lap.

The Lotus man posted a time of 1min 56.552secs inside the first 40 minutes of the session which was good enough to put him just under three-tenths of a second clear of the Toro Rosso of Daniel Ricciardo, with Lewis Hamilton for McLaren despite managing just six laps before the team elected to end its programme early to swap the engine in his car in time for FP2.

Sergio Perez was over a second off the pace and was fourth, with Felipe Massa and Mark Webber rounding out the top six.

Understandably in the conditions, a number of drivers suffered spins or trips across the grass, with Grosjean, Perez, Kamui Kobayashi, Timo Glock and Dani Clos amongst those to have moments in the challenging conditions.

Despite the wet nature of the circuit, none of those drivers to go off-track ended up in the gravel or the barriers, with everyone able to return to the track.

In total, 21 of the drivers set timed laps, with Fernando Alonso, Paul di Resta and Jules Bianchi all electing not to set a lap-time. Di Resta also suffered a steering issue that led to the team replacing the steering rack on his car mid-session.