Bernie Ecclestone, the head of Formula One, has moved to allay safety fears over the street circuits in Valencia and Singapore that will become part of the Grand Prix calendar in 2008.

Singapore is being planned as a night race but will be contested during the day if the circuit cannot be lit adequately and even though purpose-built tracks are generally held to be much safer than street tracks, Ecclestone says he has no concerns.

“There’s another street track we’ve been racing on for quite a few years that’s in the south of France - Monaco I think it’s called,” he said.

“We’ve had no trouble there, so I don’t see why we should have any trouble at these other street circuits. But of course there won’t be a race unless it is safe.”

With Valencia and Singapore new to Formula One, questions have been asked about the number of grands prix next year.

The team bosses have always argued 20 is the absolute maximum, and Ecclestone tends to agree. “They are probably right,” he added. “We’ll have to see how it all pans out. We have to see how many we really can sustain where everybody is happy, and then we’ll have a look from there.”

Ecclestone also intimated that the San Marino Grand Prix, omitted this year as the standard of the circuit was below that now expected, was unlikely to return for 2008, and refused to confirm whether France will remain as that is rumoured to be the next European venue to make way.