Protestors used the cover of darkness to to re-erect banners torn down by the council in what they believe was a "breach of their human rights".
Last night people living near Heigham Park restrung posters to the fences demanding a "proper consultation" over Norwich City Council's plans for all-weather tennis courts to replace the existing grass ones.
Each time posters have appeared in the past, they are removed by the council as landowner.
On Saturday, the group re-posted confiscated banners after a human rights professor assured them it was their political right to public self-expression, but these were swiftly removed early on Tuesday morning.
A Norwich City Council spokeswoman said: "We removed the posters and banners on Tuesday as we would any other material displayed on council property without permission.
"We do not believe we've affected anyone's rights in terms of Article 10 of the Human Rights Convention.
"We would be happy to return these items and this can be arranged."
More banners were again placed on the fence at a group meeting last night, but one resident claims she saw these too being taken down at 7am on Wednesday.
James Packham, from the Heigham Park Consultation Group, said: "It's getting ridiculous.
"We sought legal opinion from an academic fellow to the parliamentary joint committee on human rights, and he assured us the council's reason for obsessively taking down our signs was pretty shaky.
"That's why we felt so confident sticking the banners we had confiscated, and then managed to get back, up on the fence on Saturday.
"He told us that the council can only interfere with our right to freedom of expression if it's necessary and proportionate, like in the interests of national security or for the prevention of crime and disorder.
"How is taking down signs from local people saying that we want proper consultation over the proposals serving that purpose?
"It's laughable really. They seem to be patrolling the area over some non-offensive and tastefully displayed signs."
However, Mr Packham explained the group was "getting stronger all the time", with more and more residents showing up to informal group meetings.
Lucy Galvin, Green city councillor for Nelson ward, said: "I hope the council will stop trying to stifle this positive debate and launch a proper consultation on the future of this part of the park.”
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