The Boomtown Rats singer was driving with his children along the King’s Road when the accident happened.

Witnesses told the Daily Mirror that the star shouted "No! Oh Christ no!" as he ran to help the man.

The collision was only minor though, and Bob stayed with the man until an ambulance arrived to treat his injuries.

Long-term charity activist Bob had taken his daughter Pixie, 16, and his adopted daughter Tiger-Lily, 11, to a cafe, and was pulling out of a parking space.

Sir Bob told the paper: "I’m very shaken but fine.

"There was no serious harm done to anyone in our car. It’s just a shock."

A witness said: "Sir Bob had no chance."

Geldof hails Blair’s role in G8 talks - June 8 2008
Bob Geldof today praised Tony Blair’s role in the G8 Africa negotiations but warned an audience of business leaders not to "hold their breath" with regard to future action.

The star flew in from Heiligendamm by private jet for an engagement at the Yorkshire International Business Convention, in Harrogate, just as the final draft of the deal was released.

He told an audience of hundreds of business leaders: "I don’t think we’re looking at a success. They’ll make it look like a success."

He went on: "They will claim, no matter what, is an amazing breakthrough. Don’t hold your breath."

But Bob said any plaudits Mr Blair receives for today’s deal are well placed.

The Live Aid organiser said: "On this one he deserves it."

Referring to Chancellor Gordon Brown, he added: "I’m telling you, you can be proud of what these two have achieved in this country’s name.

"This guy (Blair) has fought like crazy 24 hours, all-nighters, to get them to be serious."

Answering questions outside about whether the G8 leaders had built on the Gleneagles promises, Bob said: "I don’t think they need to build on it, they need to do it.

"They are reaffirming their commitment and to me that’s meaningless."

He added: "No commitment to the poorest people in the world is optional.

"It just isn’t. Life isn’t optional."

Bob: I wanted to howl - May 16 2007
Bob Geldof has admitted he wanted to retreat into a "remote corner" and "howl into the void" when Paula Yates left him.

The musician told Hello! magazine he was devastated when his ex-wife, who died in 2000, walked out in 1995.

"The truth is, when it all happened, when she left... I just wanted to go to some dark, grey remote corner of the world and howl into the void," he said.

The former Boomtown Rat also struggled to be without his daughters, Fifi, Peaches and Pixie.

"If I hadn’t had kids, it would have been a lot easier," he said. "One person you love leaving is bad. Four leaving is 100% worse.

"I missed everything. I missed the sound of them turning in their sleep. I missed the smell of my children around. I missed the noise overhead when they ran around. I missed their presence."

Bob was further devastated when he was told he could see the girls three days a week.

"I was presented with a fait accompli - you will see them three days a week. And everyone said, ’That’s very generous’. Excuse me? How dare you tell me when I can see my children? How dare you tell me that you are being generous?

"And I’m not talking about my missus. I’m talking about the state or lawyers."