London cyclists
20,000 cyclists took to the streets of the capital on Sunday 4 August (Reuters)

London mayor Boris Johnson was among the thousands of cyclists who raced past the landmarks of London on Sunday, on a 100-mile route through the capital.

An estimated 20,000 people took part in the biggest mass bike race yet seen in the UK, which began at the Olympic Park in Stratford with Johnson waving a giant Union Flag.

The gruelling route took riders through east and central London to the heart of the Surrey countryside, along a similar route to that taken by athletes during the Olympic road races of one year ago. It then looped back into the capital to the finishing line at the Mall.

Along with Johnson, rugby World Cup winner Matt Dawson, two-time Olympic rowing champion James Cracknell, former Olympic champion hurdler Sally Gunnell and actor Gary Kemp all took part.

Later on Sunday, 150 professional cyclists including Tour de France green jersey winner Peter Sagan will follow an extended 140-mile route.

Johnson said: "This is a great day for cycling, and for this city.

"I want to thank the organisers and the wonderful crowd who made all the difference as we cycled by, helping to spur me on to finish the gruelling 100 miles in a respectable eight hours.

"Huge congratulations to everyone who took part - RideLondon is now firmly on the map as one of the greatest cycling events in the world."

Italian Wladimiro D'Ascenzo was first across the line in the Prudential RideLondon-Surrey 100 in a tight finish.

The first riders took just over four hours to finish the race, with most of the 800 enthusiastic but tired amateurs finishing about an hour later.

Lauren Whitmore, 29, who was the first woman home, told the Mail Online: "It was awesome. It's such a brilliant course with Leith Hill and Box Hill, which is so iconic, and then finishing on The Mall was great.

"I normally ride those Surrey roads on Sunday mornings anyway, just much slower. It was so nice to do it without traffic today. It was so much fun, I'll definitely be back next year."

It is hoped that the Prudential RideLondon festival will encourage more people to take up cycling, raise money for charity and bring thousands of visitors to London and Surrey.