Parents fighting Stoke Newington road closures because traffic will be diverted past their children’s already polluted school say the council got their traffic data wrong and want the scheme stopped.

CleanAir4Schools has been shown updated figures, in draft form, by the town hall, about the number of cars expected to be displaced onto Church Street should Walford, Beatty, Brighton and Barbauld Road’s be closed.

Initial data showed an extra 564 vehicles were expected to use Church Street but the latest figures show there could be 2,080 vehicles passing William Patten and St Mary’s schools.

But the town hall says that figure does not include traffic “evaporation” or reduction.

Church Street trader Heidi Early of Earlybird Cards said: “We’re horrified senior officials have got it so badly wrong. If traders and residents had been told the true impact when the council consulted, I imagine opposition would have been far higher.”

Campaigner Matt Petzny added: “Given the council didn’t fully understand the impact of its proposals, I hope they will now do the right thing, scrap these road closures and come up with properly considered plans.”

The row has been rumbling on since the plans were announced last year. Last week, families in the affected roads showed their support for the campaign.

A town hall spokesperson said: “We have worked closely with Clean Air for William Patten throughout this process and have been clear that we will only make a final decision on whether to go ahead with the changes once their expected impact is fully understood.”

A petition against the road closures has been launched.