Volunteers at a leading green project in the borough were appalled after workers for a house-building firm destroyed a patch of woodland.
Nature enthusiasts at Greenslate Community Farm spoke of being reduced to crying after Persimmon Homes contractors chopped down hundreds of trees.
The company was doing drainage work for homes near the Orrell farm but in doing so appear to have bulldozed an acre or so of green space leased to it by Wigan Council.
A local councillor has also blasted the firm and demanded the damage is put right.
However, Persimmon said it was doing work asked of it by the town hall.
Stu Hollihead, one of the Greenslate volunteers, said: “I can honestly say that for a few minutes I stood in horror, tears rolling down my face, at what had been done to this once-beautiful habitat.
“It was a scene reminiscent of the Somme. Around 500 self-seeded trees had been torn down and shredded. Around 200 trees gifted to the farm by the Woodland Trust had been totally destroyed.
“The wood chip path myself and a group of adult learners had built had been wiped out and replaced with a hardcore concrete roadway.
“Even if Persimmon’s work was essential the devastation is totally disproportionate.”
Coun Michael Winstanley, who represents Orrell, has given his backing to the devastated volunteers.
He said: “What has happened is totally unacceptable. The work volunteers have done has been totally and utterly trashed in one fell swoop.
“Greenslate is a green oasis and I hope Persimmon Homes put right the destruction they have undertaken without any quibbling whatsoever.”
A spokesman for Persimmon Homes North West said: “At the request of Wigan Council we are required to complete works which include the clearing of vegetation, installation of a footpath and the erection of a fence around the sustainable drainage system on the development in Billinge.
“We are in close contact with the appointed contractor to ensure work is completed diligently and as quickly as possible, with the least disruption to local residents.”