Fresh fears have been raised that NHS bosses are trying to engineer the closure of Norwich's walk-in centre.
The proposal to shut the Rouen Road site is among options being considered, as the contract to run it nears its end.
But the officials responsible have been accused of trying to promote this outcome through a "biased" consultation process.
Those fears have been heightened after it emerged that of the more than 5,000 people who have tried to take part in an NHS survey over the issue, just 1,600 completed the process.
Critics say the survey is flawed and that people who might want to support the walk-in centre are giving up before completing it.
Alex Stewart, chief executive of Healthwatch Norfolk, described the figure as "concerning".
He said: "If only a third of people are completing the survey, that fits in with our worries about the structure, language, and nature of the survey which was set out in our statutory letter last week.
"We remain clear that there are some serious questions to answer about the planning and delivery of this consultation and await with interest a formal response."
The consultation proposes three options for when the centre's contract ends in March 2024:
- Keeping it open
- Closing it completely
- Replacing it with an alternative service
Sadie Parker, director of primary care at NHS Norfolk and Waveney, said: "It is really important people share their views on the options and any other ideas they may have.
"We are really pleased with the level of engagement we have had and will keep pushing it so we get as many responses as possible."
She said opportunities were being created for people to have their say face-to-face and that Braille versions of the documents were being drafted.
The consultation runs until Sunday, March 26.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here