London's congestion charge is failing to reduce traffic, a report shows.
Six out of 13 traffic targets set for 2010 will not be met.
The report by Transport for London said by 2010 congestion will increase by 8% and carbon dioxide emissions are also set to increase.
Lib Dem London Assembly member Lynne Featherstone said the mayor had failed to deliver real and vital improvements.
She also accused Mayor Ken Livingstone of ignoring chronic congestion in the suburbs. Mr Livingstone said the congestion charge had worked very well.
According to the report six out of 13 traffic targets set by the government when the congestion charge was introduced will not be met by 2010.
They include reducing congestion, meeting air quality targets, reducing greenhouse gas emissions and improving bus reliability.
"The figures that the Liberal Democrats are getting so worked up about have stayed broadly the same over the last decade," said the Mayor.
"We won't be able to bring down the levels of congestion in the suburbs the only thing we can do is improve bus services.
"Since I came into power there were four million bus journeys a day now there are six million."
But Ms Featherstone said the news was a "bitter blow" to many people in the capital.
"For all the talk on reducing congestion, improving air quality and being a champion of the environment, the Mayor has failed to deliver real and vital improvements.
"The Mayor has ignored the chronic congestion in the suburbs and focused so heavily on inner London that he has forgotten the problems that blight those in the outer boroughs."
Traffic targets which are set to be met, according to the report, include reducing the number of adults and children seriously killed or injured in road traffic accidents and encouraging more people to use public transport.