Defending champion Jenson Button has backed the 'big four' to fight for honours during the 2010 F1 season - but has suggested𝓰 that three other teams could join the party dur♌ing the season ahead.

Speaking to Reuters following the final🥂 pre-season test in Barcelona, Button said he felt that his own McLaren team - as well as Ferrari, Mercedes and Red Bull Racing - would be a contender during the year ahead as the four top teams from 2009 look to fight for the crown.

However, with a number of other teams having impressed during pre-season testing, Button suggested that another three🦹 teams could realistically be regarded as potential winners for the year ahead.

"I think there are more than four teams at the front," he said. "You've got🥀 us, 🐈Ferrari, Mercedes and Red Bull, but you've also got Sauber, Force India are not far behind, and the Williams.

"So it's❀ very, very competitive, which is good to see."

Team-mate Lewis Hamilton set the pace during the final pre-season test in Barcelona, but Red Bull, Ferrari, Force India, Williams and Mer✨cedes all had cars inside the top ten on the overall time🦂s.