A petition against plans to build a large road junction on land protected by an act of parliament has been signed by hundreds of people.
The Blue House roundabout, on the outskirts of Newcastle, is congested and unsafe, the city council has said.
The authority proposes moving it and expanding it on to the Town Moor.
Sarah Edgar, who started the petition, said the scheme was "environmentally damaging, very expensive and is completely over the top in its scale".
They have been approached for comment.
The Labour-run council said the current roundabout was congested, did not work well for public transport, pedestrians and cyclists and had one of the worse safety records in the city.
The authority said it had a responsibility to ensure the junction becomes safer and does not "constrain growth" in housing and employment.
The plans are at an early consultation stage, it said.
Hundreds of people had commented online and the response had been "overwhelmingly negative", Mrs Edgar said.
Residents have called it "completely out of proportion" and a "monumental and misguided waste of money".
The consultation period - due to end on 21 August - was a "very short window for response" when many were away on holiday, Mrs Edgar said.
"This is an irreversible decision that cuts into our great city's precious green space."
Liberal Democrat transport spokesman Greg Stone said the plans were "more radical and have a far bigger 'footprint' than many had envisaged".
"We share local anxiety that this has a disproportionate impact on the Town Moor - a unique jewel in our city's crown," he said.
"We would welcome clarity as to whether the Freemen support this proposal."