Dozens of residents turned out to present a 1,300-signature petition against a controversial superstore to the leader of Worthing Council.
More than 50 members of Field Place Area Residents' Association waved placards reading "Say No to Asda" on the steps of Worthing Town Hall.
Councillor Sheila Player was there to hear their concerns and accept the petition.
The residents fear the £20 million scheme for an Asda store on Worthing College's school fields would ruin their community.
Association member Graeme Cornell said: "The handing over of the petition and protest went really well.
"We had an excellent turnout.
"It was heartwarming to see so many senior citizens there as well as young people.
"Sheila Player was very supportive of the residents.
"They are horrified at the impact the store would have on their lives. Traffic would be terrible.
"Some of our members did their own traffic counts which disprove Asda's figures. The effects would be devastating."
The plans would include a 45,000sq ft supermarket with 500 parking bays and a new access road to the roundabout.
Under the terms of the deal, the cash-strapped sixth form college would be given money for a desperately needed three-storey building.
Mr Cornell, 50, of Melrose Avenue, Worthing, said: "The college has been pushed into this deal.
"But sticking an Asda on school playing fields is not the answer.
"We are determined to stop the plans and raise the profile of our campaign.
"We send out regular newsletters and have had massive support. As it gets nearer to going to committee, we will make sure we have our members at council meetings.
"Most of us are not the sort of people who would usually protest like this. We are normal, rational human beings. But we care about our community and will do everything we can to save it."
The residents association, which has up to 600 members, has started raising money to pay for solicitors to fight the plans.
John Robinson, principal of the college in Bolsover Road, said: "The only way for us to be able to afford a new building is to sell an asset.
"We would not get enough money if we sold it for housing so a new superstore is the only way."
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