They have lobbied to save the park from being eroded by development at its edges.
Despite a council report on Castle Park advising that councillors reject the camapigners' bid for town green status for the park, the politicians sided with the parks lobbyists.
Councillors sympathised with their desire to protect the open space in Bristol's city centre.
They passed a resolution which asked the council's executive to consider granting voluntary "town green" status.
The move was welcomed by campaigners, who said they would now wait to see what happened before taking further legal action.
The issue will now go to Bristol City Council's Cabinet.
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