Residents living in a village in Wigan borough have accused a neighbouring council of 'marking its own homework' by approving the major redevelopment of a nearby colliery.
Up to one million sq ft of employment space and a link road to the M6 has been earmarked at the former Parkside site at Newton-le-Willows in St Helens.
Parkside Regeneration LLP, a joint venture between developers Langtree and St Helens council, will create more than 1,300 jobs - including 457 during construction.
The local authority gave their approval on Tuesday, but the final sign off will be made by Robert Jenrick, Secretary of State for Housing, Communities and Local Government.
Both projects are in green belt land, though the applicants argued that "very special circumstances" outweighed any harm caused by the developments.
But the Lowton East Neighbourhood Development Forum (Lendf) criticised St Helens council for acting as applicant and decision-maker.
Lendf's chairman Ed Thwaite said: “The applications conflict with national policies on important matters, and could have significant effects beyond their immediate locality, giving rise to substantial cross-boundary or national controversy.
"St Helens council is the applicant and the planning authority. The council are [sic] marking their own homework, high risk of bias, inadequate assessment and erroneous decisions."
Documents submitted in support of the scheme by planning consultants Curtins said the development would cause limited harm to the local road networks.
But this was disputed by Wigan council, which submitted one of 667 objections to the scheme.
The council’s principal planning officer Dave Rawsthorne said the borough's roads would bear the brunt of traffic leaving the site to reach the A580 East Lancashire Road.
It was argued that Winwick Lane in Lowton - the quickest way to the A580 - would appeal to drivers of light and heavy goods vehicles.
Mr Rawsthorne said: “Whilst it is accepted that a high proportion of traffic travelling to [Parkside] may be via the motorway, this doesn’t take account of traffic flows on the local network and we have no information over where deliverys to and from the site will be made.”
The council argued that Curtins had failed to consider the impact that new residential developments in Wigan borough would have on traffic in Parkside.
In Lowton and Golborne, a total of 1,281 homes have been approved since 2013.
With nitrogen dioxide levels in Winwick Lane already exceeding legal limits, Wigan council also said that air quality would only get worse should Parkside be redeveloped.
Currently the average annual limit for nitrogen oxide in the EU is no more than 40 micrograms per cubic metre of air. In 2019, levels on Winwick Lane reached 57.7 micrograms.
Mr Rawsthorne said: “The proposed development will bring about a worsening of the current exceedances and impact upon human health unless measures to mitigate the impact can demonstrate their likely effectiveness and be clearly evidence.
“No such evidence has been proposed to date.”
If the Parkside revamp secures government approval, the first phase of construction will start in 2021 and is due for completion in mid-2022.