Protesters have forced a council to stop a bat survey before four mature trees were felled.
The trees outside Newark Library in Nottinghamshire are to be cut down to make car parking spaces.
More than 50 protesters surrounded the trees to stop workmen.
The council wants a bat expert to assess the site and check if bat boxes were in use.
However, to reach to boxes with a cherry-picker he had to cut through a hedge.
As both sides faced up to each other the police were called.
The protesters wanted to ensure a “wildlife crime” wasn’t being committed.
And the council wanted to guarantee there was no breach of the peace.
The “Stop the Chop” campaigners also fear cutting through the hedge would mark the start of work.
The council has until the end of the month to fell the trees before planning permission on the car park runs out.
One protester said: “On the day Cop26 begins, they’re talking about arresting old ladies.
“The council has stooped to a new low.”
Another protester said:
“They have kids and need their open spaces too.
“I can’t understand why this is happening.”
Campaigner Jay Henderson, A Green Party town councillor, said:
“People will stay here to see what their next move is.
“I have seen some strong determination here.
“We will be here long term.
“People have said whatever direct action they need to stop these trees being felled, and that is a matter of choice.”
Keith Girling, deputy leader of Newark and Sherwood District Council said:
“An independent fully qualified ecologist, accompanied by council officers, visited the site at London Road carpark today to undertake an up to date ecological report.
“This report would have identified whether or not there were bats present at the site as the protesters have claimed.
“However, during the visit a group of around 50 protesters stopped this survey from happening.
“To date, those campaigning against the loss of trees have expressed their views with passion and respect but disappointingly, things took a turn for the worse today.
“Staff were verbally abused, called ‘scum’ and intimidated during the course of their duties. That’s completely unacceptable.
“The council was faced with a tremendously difficult choice of retaining four trees at a cost of £600,000 and decided that, notwithstanding its commitment to the environment, this was too high a price to pay given its responsibilities to local tax payers and the whole of Newark and Sherwood.”