Tree campaigners say Sheffield Council 'wasted' thousands of pounds of taxpayers money through what they have called unnecessary court action.
The authority is facing a bill of over £250,000 following three hearings relating to its tree felling and replacement programme - which campaigners say could have been avoided through conversation and consultation.
The most recent court case, when the council successfully won an injunction stopping people from protesting inside safety barriers in August, cost almost £150,000 in lawyers' fees and officer time, according to the authority.
Cabinet member for the environment Bryan Lodge initially said the authority would pursue the three named defendants, Coun Alison Teal, Dave Dillner and Calvin Payne, for full costs. But it eventually settled for £1,000 from each campaigner - meaning the rest will come from the existing council budget.
The council also spent just over £100,00 successfully fighting a judicial review against the felling process, brought by Mr Dillner last year.
Those figures do not include the 'significant' cost of technical and support staff before and during the hearings, said the council.
And this is on top of the cost of the independent tree panel, brought in to address campaigners' concerns. The panel looked at 788 trees and recommended 316 should be retained. The council took that advice on 73 occasions.
Coun Lodge said the authority had taken a 'pragmatic' approach and sought the 'best possible deal for taxpayers'.
"Ultimately, the street tree replacement programme was found to be lawful on all counts by a High Court judge and an injunction was granted to prevent trespass within safety barriers around tree works," he added.
"Further legal action to recover higher costs would have resulted in associated fees, making the exercise somewhat counterproductive.”
A spokesman said the council, rather than Amey, had to foot the bill due to the authority's legal duty to maintain the highway.
But campaigners say the money has been wasted.
Coun Teal, a Green Party member for Nether Edge and Sharrow, said: "The council approach has been confrontational all along - they have rejected informal and formal mediation, preferring to crush the opposition using the full force of the law rather than talk to people.
"This council has a duty to explain why it wasted taxpayers money taking campaigners to court when the PFI contract clearly states that Amey bears any loss caused by protesters.
"Surely it would have been prudent to enforce this aspect of the contract?"
And Rebecca Hammond, co-chairman of Sheffield Tree Action Groups, known as Stag, added: "We are ready to talk.
"In fact we’ve approached the council recently to discuss how talks might be organised.
"But unless there is a genuine wish to explore ideas that might be acceptable to all three parties - Amey, the council and the tree campaigners - and save a good number of healthy trees, there seems little point."
The council aims to fell and replace 6,000 of the city's 36,000 street trees under the £2 billion Streets Ahead PFI contract with Amey. The authority says only those that are dead, diseased, dangerous or damaging the highway are coming down.
But campaigners disagree. Mrs Hammond said she had 'never seen' a convincing explanation of why healthy trees had to be felled.
The council this week reiterated its warning of further court action against people who break the injunction after protests stopped felling in Kenwood Road, Nether Edge - where environment secretary Michael Gove had earlier visited.