The chairman of a voluntary group says relations with a council-run trust managing the city's Pearson Park have completely broken down.
The Friends of Pearson Park group has been running for about seven years.
But its chairman Dr Haris Livas-Dawes says relations with the Pearson Park Trust, which is made up of councillors, have all but collapsed.
She said: "You would think the trust would want to work in partnership with a group of volunteers who share a passion for the park and are prepared to devote a lot of their time and energy to improving it.
"However, the exact opposite seems to be case."
Dr Livas-Dawes said three incidents over Christmas had brought things to a head.
She claimed the trust had refused plans by the Friends to install a sign promoting a new health trail and had also vetoed the idea of having a "community Christmas tree" for people to decorate outside the park's café.
Instead, the trust went ahead with its own decorated tree near the park's Victorian conservatory
She said the final straw came when the trust refused to meet members of the group to discuss a new list of suggested priorities for the city's oldest public park.
"The park belongs to the people but we have a situation here where a group of councillors meet behind closed doors as trustees and try to dictate what goes on in the park.
"They tend to forget they were elected as representatives of the people."
Dr Livas-Dawes said her personal relationship with trust chairman Councillor John Fareham was not good, having previously lodged a standards board complaint about his alleged behaviour towards her during a council meeting.
She said: "I don't particularly care for him and I'm sure he doesn't particularly care for me but that should not get in the way of how the trust should be working with the Friends.
"It's not just about two individuals, the Friends have got 70 members who all want to see the park flourish.
"Unfortunately, the trust appears to be hellbent on standing in the way of everything the Friends want to do."
Cllr Fareham said he was "disappointed" at Dr Livas-Dawe's remarks.
He said: "It's probably true we don't care for each other that much but this is not about individuals.
"The trust is there to run the park and that is something Dr Livas-Dawes has never been able to understand.
"We decided the sign wasn't necessary because people don't need to be told where to walk or jog.
"It is a park with footpaths for walking and jogging on.
"We didn't have any problem with the Christmas tree, apart from the suggested location and eventually it went up at the Pearson Park Hotel.
"As trustees, we have to adhere to the trust deeds and manage the park accordingly."
