The creation of up to 500 jobs is in doubt after a judicial review was launched into plans for a £50 million warehousing development in west Suffolk.

Marketing and logistics firm Prolog recently gained planning permission to expand by building two huge warehouses on land in Sudbury’s Church Field Road.

But Lady Valerie Hart, who lives at the nearby Grade II listed Chilton Hall has submitted an application for a review of the proposal to the High Court.

In the next three weeks, a judge will decide if a legal challenge should go ahead.

The project has been beset with delays while Prolog and the council’s planning officers negotiated a list of workable planning conditions.

A group of Chilton residents including Lady Hart have campaigned against the development because of the vast size of the buildings and the harm they could do to heritage assets including Grade I listed St Mary’s Church and Chilton Hall.

Lady Hart told this newspaper she had made an application for a judicial review on eight different grounds.

Meanwhile Peter Clifford, chairman of Chilton parish council, agreed that a judicial review was necessary. He said: “We came down against this on the grounds that it’s too big, not in the right place and is detrimental to the church and hall, which Babergh has acknowledged.

“Most significantly, we don’t believe the promised jobs are there and the conditions have been watered down so that Prolog could just walk away from this in a few months or sell it to someone else.”

Babergh’s recently ratified core strategy set a target of 9,000 new jobs in the district by 2031.

Prolog already employs more than 400 people at its Milner Road plant and its expansion plans have been ongoing for almost a decade. If it is unable to grow, the company has threatened to relocate its entire operation to the east Midlands with the possible loss of around 900 jobs in total.

Last night, a Babergh spokeswoman confirmed that Lady Hart was seeking to challenge the council’s decision by a judicial review.

She said: “Babergh considers its decision to grant planning permission for the Prolog development has been lawful, is in line with our strategic priorities around economic growth and will defend its decision robustly.”

Prolog has consistently reiterated its commitment to Sudbury. One of the directors, Peter Tyer, said they could now only “wait and see”.

He added: “We are disappointed but given the threat that was made quite clearly at the (Babergh planning committee) meeting, the judicial review is no surprise.”