• Ecclestone describes some teams 'are a bit out of their depth' • Harsh financial climate takes its toll on F1

The Formula One supremo Bernie Ecclestone has suggested that one or two teams may not complete the season as financial constraints take their toll on the sport.

Big and small teams alike have suffered. Williams will lose their main sponsor the Royal Bank of Scotland at the end of the current campaign, Renault have been at the centre of stories suggesting they wanted an advance from Ecclestone on television rights money, while Hispania Racing have announced that Sakon Yamamoto of Japan will replace India's Karun Chandhok at the Hungarian grand prix as pay drivers are left out for not coming up with sufficient funds.

Ecclestone, the sport's commercial rights holder, said in the Daily Telegraph that he felt some teams were out of their depth. "I would be surprised if one or two of them make the end of the season. I think there are a couple of teams who really shouldn't be there. They are a bit out of their depth at the moment."

He added that a 10-team championship was all that he really needed. "All we ever want is 10 teams," he said. "In general this year has been a bit of a nuisance because it has cost money to keep these teams in.

"The bottom line is they haven't really and truly given us value for being there."