Campaigners fighting against the ongoing felling of trees in Sheffield say they have been "amazed" by the response of people who live on the streets affected.
Chris Rust, treasurer of Sheffield Tree Action Groups, said he felt protests would only intensify as council contractor Amey, carrying out the work as part of the £2.2 billion road improvement programme, continue their work.
Mr Rust said: "We think that the ramping up of the amount of force used by Amey was inevitably going to lead to more problems on the streets.
"It's clear that Amey's ability to manage their work is inadequate. We fail to see how they can go any further with this."
Arborists are felling trees deemed dangerous, dead, diseased, dying or which are said to be damaging streets and pavements.
Objectors to the scheme have staged a number of protests across the city, with demonstrations now held on a daily basis.
There was a disturbance in Meersbrook Park Road, Meersbrook, on Monday, when a campaigner fighting to save the trees clashed with security staff, who have been given permission to physically remove trespassers from safety zones.
Mr Rust added: "I am amazed by the way the residents in Meersbrook have come out on the streets. We have seen families doing everything they can."
Trees earmarked for felling are fenced or cordoned off and a court injunction is in place making it illegal for protesters to enter the safety zones.
But a number of cordons have been breached, leading to a number of stand-offs.
Mr Rust, of Nether Edge, said there were several reasons protesters were breaking the law by entering safety zones around trees earmarked for felling.
He said: "The protesters believe Sheffield City Council have made stupid, fundamental mistakes and they believe there is a point when the law becomes unjust and there is a strong tradition of doing so in this country - that's how laws are changed.
"Most of the people are not breaking the law but the resistance will probably go on for as long as people are angry and it seems that every time Sheffield City Council and Amey do something more serious to clamp down on it, the protesters step things up."
An Amey spokeswoman said: "We welcome safe and peaceful protest but unfortunately this is not what we experienced in Meersbrook Park Road on Monday.
"In the interests of everyone’s safety we withdrew from site, and we will resume as soon as we can ensure the safety of our staff, local people and the protesters themselves.
"Re-planting certain street trees which are ailing or damaging is one of the ways we deliver the council’s legal duty to maintain the city’s highways, which is why a High Court injunction is in place to keep our working areas safe.
"We urge people to respect peaceful communities and not to wilfully obstruct our works on the highway by staying outside the safety zones, so we can complete this programme for the benefit of everyone in Sheffield."