More than 1,140 people have objected to plans to build up to 618 homes on the outskirts of Stevenage, but a local authority has “let us all down very badly by welcoming and supporting it”, says one of its own members.

The developer – Pigeon Land Limited – also wants to create a primary and pre-school, an 80-bed care home, up to 50 assisted living homes, shops, community facilities, a site for travelling showpeople and a spine road on the agricultural land to the east of Stevenage, on Gresley Way – between Fairlands Way and Lanterns Lane.

East Herts District Council – which will determine the planning application as the site lies entirely within its boundary – has received 1,146 objections to the development, and just six in support.

Concerns include traffic congestion, insufficient infrastructure and loss of the Beane Valley view.

Stevenage Borough Council heard from concerned residents at a full council meeting last Wednesday, after more than 1,000 people signed a petition calling for SBC to object to the development.

SBC said it did not raise any objection to “the principle of a well-planned residential extension to the east of Stevenage” during the preparation of the East Herts District Plan, but has now drafted a 12-page report expressing significant concerns about several aspect’s of the plan’s provisions, including affordable housing and education and health provision.

Councillor Robin Parker, a Liberal Democrat who represents the Manor ward on Labour-controlled SBC, has called it an “appalling development”, with Stevenage “expected to provide the various services required by the residents of Gresley Park”.

He said: “Unfortunately, Stevenage Borough Council let us all down very badly by welcoming and supporting it, with a few reservations.

“All we can do now is send our objections to EHDC and see if we can get some improvements. The EHDC meeting will not be until May 22 at the earliest, so you can still object, even though it is now after the official deadline.”

Councillor John Gardner, SBC’s executive member for environment and regeneration, said: “The development is entirely within the jurisdiction of EHDC and the Lib Dems have been misleading people into believing we could do anything other than comment on the provision made for services to accommodate the additional homes.

“Our task prior to the application being determined is to work to minimise any negative impact on Stevenage and ensure the new neighbourhood is a sustainable development.”

Councillor Jackie Hollywell, executive member for community safety and ward member for Chells, added: “I share the concerns expressed by residents, and in particular the increased traffic on Gresley Way and the road to Walkern, and call on the county council to ensure the highways issues are highlighted and assessed thoroughly.”

More than 760 people have joined Facebook group Say NO to Gresley Park and more than 920 people have joined the Gresley Park Interest Group.

More than 530 people have signed a petition calling on the developer to avoid the need for three new junctions on a short stretch of Gresley Way directly opposite Chells Manor and come forward with proposals to mitigate the traffic impact on adjacent country lanes leading to Aston and Walkern.

Aston Parish Council has objected to the plans, with clerk Roy Falder saying: “No account has been taken of increased rat running flows on Lanterns Lane and hence Aston. We want to see measures put in place to mitigate this.”

The site, which contains protected species, is also an area of archaeological interest after prehistoric pottery consistent with a Middle Iron Age date was found.

An historic environment adviser at Herts County Council said: “A relatively small number of Middle Iron Age sites have been identified in Hertfordshire, so the identification of this ceramic assemblage is potentially significant.

“The position of the proposed development is likely to have an impact on heritage assets of archaeological interest.”

An archaeological field investigation prior to any site development has been recommended.

A spokesman for Pigeon has previously said: “The planning application has been submitted in accordance with the adopted East of Stevenage Local Plan allocation and will deliver a high quality landscape-led scheme.

“As with all planning applications, comments on the scheme will be considered during the application process.”

A general residents’ meeting with SBC Lib Dem councillors for Manor and Chells and for HCC’s Chells division will be held at Chells Manor Community Centre, Emperor’s Gate, on Monday at 7.30pm – with Pigeon representatives due to be in attendance.