Defending cham🔯pion Jenson Button has backed the 'big four' to fight for honours during the 2010 F1 season - but has suggested that three other teams🌟 could join the party during the season ahead.

Speaking to Reuters following the final pre-season teಌst 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 durinꦆg 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 B🤪ull, but you've also got Sauber, Force India are not far behind, and the Williams.

"So it's very, very comp🐼etitive, which is good to see."

Team-mate Lewis Hamilton set the pace du✤ring the final pre-season test in Barcelona, but Red Bull, Ferrariꩵ, Force India, Williams and Mercedes all had cars inside the top ten on the overall times.