A war of words over whether a town's air quality is good enough is not over.

It was early in October that members of Maidstone council's environment committee heard from the borough's scientific officers that air quality had improved across all the points within the existing Air Quality Management Area (AQMA) except one.

The zone had been first established in 2008, because at the time the level of nitrogen dioxide (NO2) in the air had exceeded the permitted level of 40mg per cubic metre at a number of locations. That is the limit where the council is legally obliged to take action to protect public health.

The committee accepted the officers' advice that the AQMA could now be shrunk in size to just the one area where pollution still exceeded legal limits – which is Upper Stone Street between Wrens Cross and the junction with Old Tovil Road.

The decision was ratified by a meeting of the council's executive at the end of the month, with council leader David Burton (Con) saying: "We all know that air quality affects every single one of us.

"But this is good news. Pollution has reduced. Reducing the size of the AQMA will enable us to concentrate all our effort on improving the worst bit of the borough."

But on both occasions the reduction was challenged by the borough's sole Green party councillor, Stewart Jeffery, who argued that although pollution at the monitoring stations was now below the legal limit it was still above that recommended by the World Health Organisation.

Now Cllr Jeffery along with Labour councillors Maureen Cleator and Paul Harper have "called in" the decision for review by the overview and scrutiny committee, which could refer the matter to a meeting of the full council

Cllr Jeffery said: "While I can see that there has been a tiny improvement in air quality, to reduce the AQMA in such a drastic way will simply reduce the focus and effort that the council needs to bring this widespread problem, one that kills a huge number of people.

“The data the council is relying on still shows that 90% of the town is above World Health Organization guidelines."

Cllr Cleator said: "The borough has based its decision on just one year's worth of data.

"To reduce the area just flies in the face of common sense. We all know that traffic congestion is increasing at many points around the borough and we must think of the health of the people who live near those hotspots."