Protesters opposed to a new 15,000-house development on countryside in Leicestershire have taken their concerns to the developer.
Members of the Campaign Against Stoughton Co-op Eco Town held a "noisy" demonstration, including songs, outside the Co-op in Oadby.
They hoped to gather more supporters by highlighting their concerns over loss of green land and increased traffic.
The Co-op has said its proposals would boost the local economy.
The government has received about 60 applications nationally for new settlements designed to provide a carbon neutral solution to the housing problem.
Campaigner Anne Bond said they intended to make their presence felt at Westminster.
"We hope very much that the government will be listening that all the local residents don't want a great big town the size of Hinckley plonked in the middle of their green and pleasant land," she said.
Edward Garnier, Conservative MP for Harborough, supported the protest, arguing that the plans would "not only damage rural Leicestershire but Leicester ... The whole thing is a disaster".
A shortlist is expected to be announced later this month, followed by a final decision in the summer on where the 10 eco-towns will be.