An action group which is campaigning against plans by a Cornish school to sell a playing field to Tesco has called for it to "listen to the people of the town".
Newquay Tretherras Academy has come under fire over plans to sell a playing field.
The school's chairman of governors, Richard Simeons, said previously that the sale was vital to fund renovations and improve facilities at the school over the coming decades.
He said the "grassy area" was not a designated sports field and sport would not suffer if it was sold.
But Valerie Martin, chairman of action group Residents Against Inappropriate Development (RAID), which is campaigning the plans, said if approved the plans would "alter the face of Newquay forever".
In an open letter to Mr Simeons, she said: "This decision has huge implications for the whole community and many businesses and should not be taken by a few unaccountable people.
"Before you make the decision, listen to people of the town. We all want the best for the children and young people of Newquay now and in the future.
"Are you prepared to alter the face of Newquay forever, without any consultation with the people of Newquay?
"Mr Simeons, we the people of Newquay hold you accountable; please draw on your integrity and honour the children and young people of today and the future and respond by withdrawing your plan to sell to a supermarket and invite the people of Newquay to join with you in raising money for the needs of the young people."
The calls come at a time when the Government has been criticised for agreeing the sale of 21 school sports fields in the past two years.
Secretary of State Michael Gove has been accused of opening the way for more sales by relaxing the minimum space schools must provide for outdoor sports.
Mr Simeons said nothing was being done "in secret" and he was happy to talk to anyone about their fears.
"If we move forward we will go, as we have always said, to public consultation," he said. "Then it is moved into planning and everybody has the opportunity to object to the plans.
"The governing body and the teachers are fully aware of their responsibilities to the education of the students now and in the future and we are also very aware the role sport plays in the school."