UP to 200 jobs are at risk in local shops if a new Tesco supermarket opens in Penistone, it was claimed today.
A new campaign group said a store of the size planned was not justified.
Penistone Residents Against Large Supermarkets was formed after a packed public meeting in the town.
Spokesman Pete Riley said: "We are very concerned about the impact of a store of this size on other businesses in the area. We want a major rethink."
The proposed Tesco store is part of a £15m redevelopment of the Penistone markets area.
Plans include a new market and new fire and ambulance stations.
The design follows a planning brief set by Barnsley Council.
Mr Riley said the council had refused to release the key document justifying the plans.
He said: "If Barnsley think it is right then they should release the report on which they based their decision.
"It is pretty clear that if Tesco gets the go-ahead they want to attract customers from a huge area, which will generate more traffic."
It is expected Barnsley Council will consider the applications early next year.
Mark Dransfield, managing director of developers Dransfield Properties, said: "There is widespread support for this long awaited development and the submission of the planning application is another step nearer to redeveloping this area of Penistone."