A Lynn sports ground has not yet been protected for future generations, more than a year after a pledge that it would be, it has emerged.
Council officials say they are exploring alternative options for the River Lane pitches after they found they could not proceed with their original proposal.
But campaigners say they are worried the land could still be included in future housing development proposals.
Concerns were first raised for the future of the site when it was included in plans for a major new housing development around the Lynnsport and Marsh Lane areas almost two years ago.
But the site was removed from the project in January last year, in response to the weight of public opposition.
And, last summer, West Norfolk Council leaders approved plans to register the land with Fields In Trust, a national charity which safeguards recreational spaces.
The move followed an earlier pledge that the site would be protected from any future development ideas.
However, this week, the authority confirmed that work had not been done.
A spokesman said a Fields In Trust registration would have prevented the council from allowing parts of the ground to be booked out for use, as can be done at the moment.
But she added: “We are exploring the possibility of a self-imposed covenant that will offer the same protection as the Fields In Trust initiative.
“A report on this approach is being prepared and will be presented to cabinet shortly.”
But no firm timescale has been given for when the new proposals will be published.
And Sue Bruce, secretary of the Lynnsport Area Residents’ Association (LARA), which has opposed developments in the area, said she was concerned the land could still be developed in the future.
She has called on the authority to act quickly to resolve the issue.
She said: “I just want to see what they promised. They promised it. Let’s see them do it.”
Around 150 homes were originally proposed for the site, which was referred to as Lynnsport 2 when it was part of the ongoing project.
Almost 400 more houses are planned for five other sites around the area.
Two of them, Marsh Lane and Lynnsport 3 have already been granted planning permission.
And the latest phase of the scheme saw a public consultation relating to plans for the Lynnsport 1 site take place in the sports centre’s Pelicans bar last week.
Proposals for the Lynnsport 4 and 5 sites, which lie either side of Greenpark Avenue, were also on display.
Mrs Bruce said she recognised it was likely development of the other sites would eventually proceed.
But she argued that protecting River Lane would show the campaign had at least enjoyed some success.
However, the council has consistently highlighted its provision of new open spaces and improved sports facilities as part of the development.