Islington Council has apologised after publicising that pollution levels were falling in areas where a low traffic neighbourhood (LTN) is in action - when the levels were in fact rising.

Highbury West and Highbury Fields LTNs are among the schemes which have seen residential roads closed to through traffic to stop rat running.

The council has said it will create ‘a cleaner, greener and healthier’ borough. But the contested schemes have been criticised for making other streets more congested, causing greater pollution.

In October last year,, results gathered by contractor Project Centre were published, showing the authority’s six month review for the trial of the eight Highbury schemes reported air pollution had fallen.

But an audit earlier this month completed by Project Centre’s successor company Systra found pollution had actually risen 26 per cent in Highbury West and Fields neighbourhoods.

An Islington Council statement read: “We’ve introduced [LTNs] as 18-month trials, and we carefully review before deciding on whether each scheme should be made permanent, changed or removed.

“We ended the contract with [contractors] Project Centre due to concerns about the general quality of work.

“Therefore, we have commissioned independent consultants Systra to produce the monitoring reports for our programme going forward. We are confident their methodologies, presentation and interpretation of the available data is accurate and in line with industry best-practice.”

The October report produced by Project Centre has now been superseded by the Systra one.

The council’s statement added that the public consultation for Highbury closed on March 14 and results would be analysed.

“We would like to thank those who provided feedback on the six-month interim report for the Highbury schemes, and apologise for any confusion,” the statement added.

Joanna Sargent, a resident who set up the Keep Highbury Moving group, was unimpressed.

She said: “The Highbury LTN trials have been incredibly divisive, so it was obviously critical that monitoring results reports published by Islington Council, showing whether the trials are meeting their objectives, be accurate and reliable.

“The council should now be urgently arranging a full and independent audit of all of its LTN trial monitoring reports.”

A Project Centre statement added: “While the body of the report correctly reported on the air quality monitoring, including all text and figures, Project Centre apologises for the human errors made in parts of its analysis. We are reviewing our procedures."