The number of cyclists killed and seriously injured on Britain's roads rose by 11% between 2004 and 2007 despite no significant increase in cycling, a report by the National Audit Office has disclosed.

It says despite an overall fall in the number of road deaths, the UK is behind other advanced industrial nations in terms of the number of cyclists and pedestrians who are injured and killed on the roads.

The report says that after falling throughout the 1990s the number of cyclists seriously injured or killed increased by 11% from 2004 to 2007. In 2007 alone 646 pedestrians and 136 cyclists were killed and 30,000 pedestrians and 16,000 cyclists injured.

The auditors found that a high profile advertising campaign to cut road deaths called Think! appeared to have little measurable effect on road casualties.

The report says the most dangerous place for cyclists and pedestrians is London. Seventeen pedestrians per 100,000 people are killed in the capital, compared with a national average of 11.

Tory MP Edward Leigh said: "In terms of the number of child pedestrians killed as a proportion of the population, we are way down the league. Our poor performance should be a matter of national debate."

Separate research published by the Cyclists Touring Club (CTC) found that where there are more riders on the roads there is generally a lower accident rate, contradicting a notion that a mass of inexperienced riders taking to the streets brings a spike in injuries and death.