Sheffield city council has pledged to save nearly 100 trees that were marked for felling as it sought to defuse a bitter row that sparked scores of arrests and months of protests.

The council has been locked in negotiations with campaigners over the future of its controversial scheme to fell thousands of trees to improve the condition of the city’s streets.

It paused tree-felling work in March after Michael Gove, the environment secretary, accused the council of “environmental vandalism” for chopping down around 5,500 trees and replacing them with saplings.

The council insisted the trees it felled, under a £2bn PFI contract, were either dead, diseased, dying or dangerous – a claim the campaigners bitterly denied.

On Thursday the council announced what it described as “a step in the right direction” after agreeing to reduce the number of trees being felled.

The council said around 87 of the 305 trees earmarked for felling in the next five years could be immediately saved, and another third would be phased over the next decade “meaning that fewer trees than previously anticipated will be replaced”.

A council spokesman said there was a joint acknowledgment from both sides that “healthy street trees should only be replaced if no other practical solution can be found, and, ultimately, that work to improve the city’s highways is welcome and, moreover, needed”.

The council said it would soon inspect dozens of street trees previously identified for replacement with a view to saving as many as possible.

Paul Brooke, the co-chair of Sheffield Trees Action Group, which drew up the joint declaration with the council, said confirmation that dozens of trees would be saved should be “hugely welcomed”.

“What this shows is a victory for very determined residents of Sheffield who always said talk to us and we can sort this out. The talking has paid off and we look like we’ve got some way forward.”