Formula One world champion Jenson Button pulled up in Bristol yesterday and had hundreds of fans baying for his autograph.

The motor-racing star's followers came from all over the country to meet him face- to-face as he chose Waterstone's at Cribbs Causeway for one of only two signings of his new book, My Championship Year.

Somerset-born Button, who has made headlines this week by switching from the Brawn team to McLaren to race alongside fellow Brit and ex-world champion Lewis Hamilton, grinned from ear to ear as he saw hundreds of people queuing in front of him.

More than 400 people stood patiently in the queue that snaked its way outside into the car park; some had been waiting for more than five hours.

Richard Hirons was the envy of everyone, at the very front. The 63-year-old who had come from Lydney in the Forest-of-Dean, said: "I'm well-chuffed. I've got two books signed. One for me and one for my six-year-old grandson Cormac's birthday."

As Button signed his autograph and posed for pictures, many asked him about leaving a title-winning team to join McLaren.

"It's going to be one hell of a challenge but it's good," he said.

Asked if success had changed him, he said: "For sure, everyone changes. The experiences I have had in the last 12 years I could never have imagined as an 18-year-old but you had better ask my friends who I went to school with.

"Hopefully the important things are still intact."

The youngest fans who attended were Jacob and Charlie Cuthbert, three-year-old twins from Chippenham. Mum Angela, 39, said: "The boys both love Formula One and have been so excited to see their favourite driver."

Michael Brooks got books for himself and his son Jonathan. The 43-year-old of Backwell said: "I was just doing my shopping when my son sent me a text saying Jenson Button was going to be here."

Button, 29, who secured motor racing's top prize in October, now lives in Monaco but has a road and a pub named after him in his birthplace of Frome. He joined F1 in 2000.

Waterstone's branch manager Abbey Allen said it was the biggest signing the store had ever had. She said: "Jenson is a local boy who captures everyone's imagination."

My Championship Year is out now and costs £20.