Over five million vehicles were captured travelling in and out of Cambridge in just one week, a survey has recorded.

The Greater Cambridge Partnership survey was carried out over eight days in June by an independent firm which used more than 90 automatic number plate recognition (ANPR) cameras to capture vehicles around the city.

The cameras found that over half of vehicles travelling into and out of the city – 55.5 per cent - were diesel, but also showed that many vehicles were found to be older than Euro 4 emission standards.

A Greater Cambridge Partnership spokesman said: “If Cambridge copied London’s recently introduced ‘Toxicity Charge’, those vehicles would face a charge.

“Alternatively, if a charge was based on the forthcoming London Ultra Low Emissions Zone principles (levying charges on petrol vehicles older than Euro 4 and diesel vehicles older than Euro 6) the survey results indicated that around 60 per cent of vehicles would face that charge.

“Improving air quality is a key priority for the Partnership. They are currently researching creating a Clean Air Zone in the city, which could involve a pollution charge or restricting vehicles due to their age or emissions.”

The study comes in the same year that an air quality monitoring kit set up by the Fenland Green Party in March found that the town’s air contained a dangerous level of nitrogen dioxide.

The air was found to have 46.202 micrograms of nitrogen dioxide (NO2) per cubic metre – over six micrograms more than the EU legal limit of 40.

That alarming figure means that March, which has a population of just over 23,000, is on par with cities such as Birmingham and Cambridge, which have populations of 1.1 million and 124,000 respectively.

Ruth Johnson, the party’s parliamentary candidate for NE Cambs, took the study to Cambridgeshire County Council and said it could be stifled by reducing the speed limit to 20mph, but her campaign was knocked back.

“Reducing the speed limit would only cost around £15,000 and wouldn’t cause any disruption – all that’s needed is a few signs around town.

“I have a young child and asthma and I moved here to get a better quality of life - but with the air pollution figures we found I might have been better staying in London.”