Cash and carry retail giant Costco wants to build a 14,030-square-metre megastore on the old John Lewis site on Stevenage’s Cavendish Road – but locals say they haven’t been properly consulted, and the deadline for public views is tomorrow.

The firm filed applications with Stevenage Borough Council last month to have the Grade II-listed building redesignated for use as a members-only warehouse club with parking for 611 cars.

Objections to the plans focus on the traffic Costco’s arrival might cause on Gunnels Wood Road, with a housing estate directly opposite.

“We’re the only residential estate around here, and the traffic out onto the dual carriageway is quite bad as it is,” said Catherine Baker, 42, who moved into Angotts Mead eight years ago partly because she thought it would be a quiet place to live.

“In the plans they talk about traffic lights, which we think would cause tailbacks as people use the road as a thoroughfare to the A1(M).

“Some of the neighbours and I are trying to raise awareness about this.It’s difficult, really, as I can see we need something else in Stevenage, but I think there are other sites that could be considered.

“I like shopping in Costco myself – I didn’t think I’d be living opposite one, though.”

Support for the plans came from Mark Agnew, of Canterbury Way.

“While I accept the development may lead to an increase in traffic in the immediate vicinity of the store this should not be considered in isolation,” he said. “I know members of Costco who drive to Watford. A store here would result in an overall reduction of vehicle travel across the county, and on the A1(M).”

A transport assessment carried out for Costco suggested that there would be more traffic around the site on weekday afternoons and at weekends, but not so much that it would exceed government guidelines. It predicted little to no impact on the A1(M).

Costco’s James Cheesemore said: “We have adhered totally to the consultation process here. 21 days is the statutory application period defined by the council. We have no control over that.”

When asked if Costco had taken steps to raise local awareness of the application with leaflets or letters, he replied: “We did not.”

The building has Grade II listing because of its idiosyncratic reinforced concrete roof, designed by the noted architect Felix Candela.

The Costco plans say that this will be retained if their scheme gets the green light.

To have your say, visit publicaccess.stevenage.gov.uk/online-applications and use reference numbers 15/00702/FPM and 15/00703/LB.