A petition calling for West Norfolk Council to 'Save Lynn's Wild Woodland and Wetland' has been signed by Stephen Fry and has gained more than 1,800 signatures.
The proposal could see 379 homes built on land near Queen Mary Road and a new bridge across the Sand Line rail link.
But protestors are urging the council to "abandon plans" to build these houses at Parkway, near King's Oak Academy, in King's Lynn.
West Norfolk Council, which is the applicant, was due to hold a special planning meeting on Monday, January 18 to discuss the plans but a borough council spokesperson said this has been postponed following a "technical issue" with the application which needs to be resolved.
They added: "A date has not been set as to when this will go to committee."
The 38 Degrees petition, which has now reached 1,804 signatures, said the area is King's Lynn's "last truly wild place."
It added: "It's a precious place, irreplaceable, nature's deposit account for all the people of King's Lynn and west Norfolk."
And campaigners got the backing of actor and author Mr Fry after contacting him on Monday asking for his support.
Jenny Walker, creator of the online petition, said: "In September, people from different environmental groups went to the Parkway site and were totally surprised to see the lovely wood and vast reed bed.
"They organised an outdoor art gallery and were joined by lots of local people, sad about the idea of losing this wild and unspoilt place.
"Rather than destroying green spaces we should be taking measures to conserve them.
"Rather than building new roads into housing estates, we should be creating low traffic neighbourhoods with quieter, safer streets for our children.
"Yes, build houses but not when the cost to people living nearby is potentially so great."
Pallavi Devulapalli, who is among those opposing, said if given the go ahead it would also have a devastating impact on wildlife and access to green spaces for local people.
A planning statement said the intention is to develop the site "to deliver new market and affordable homes in an area of housing need and strong housing demand," and to deliver a new bridge to benefit proposed new residents and existing residents of the Fairstead and Gaywood housing estates.
In response to the petition, a council spokesperson said: "It will be reported to councillors in the officer report and the contents will be taken into account in the determination of the application."
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