Britain's Jenson Button made up for lost time by giving his new Brawn GP Formula One team an impressive test debut at the Spanish Grand Prix circuit yesterday.

Apart from a brief shakedown of the Mercedes-powered car at Silverstone last Friday, Button had not been behind the wheel since November - the month before Honda announced they were pulling out of the sport due to the credit crunch.

Honda sold their team to Ross Brawn, the Honda team principal and former Ferrari technical director, last week in a deal that kept 10 teams on the starting grid and rescued Button's flagging career.

After going quickest in the morning, Button ended with a fourth best time of one minute 21.140 seconds - comfortably quicker than his fastest lap for Honda of 1:22.353 at last year's Spanish Grand Prix.

The Brawn was 0.802 off the pace set by BMW-Sauber's Nick Heidfeld, with Toyota's Jarno Trulli and Ferrari's Kimi Raikkonen also quicker than Button.

Heikki Kovalainen's McLaren, the same one that Button's compatriot Lewis Hamilton will use to defend his title, was the slowest car on the circuit.

Honda's British-based team had a miserable season last year, with Button scoring just three points from 18 races.

However, they had been hoping for a big step up in performance this year and Brawn said in December that the new car was a potential race winner.

The Briton has said his team hoped to make a "respectable" start to the season at the first race in Australia and yesterday's showing suggested they would do more than just make up the numbers.

The team's trucks were lined up in the Circuit de Catalunya paddock with their new name on the side while the car ran without branding in black, white and yellow livery.

Brawn was also present at the Barcelona test, as was the team's second driver Rubens Barrichello.

Mercedes have replaced Honda as the engine provider, with the new V8 unit believed to be providing around 60 hp more than the one used by Button last year.