Network Rail tree felling opposed
The government is being urged to stop Network Rail cutting down trees along its tracks.
Labour MP Jeremy Corbyn is leading calls for the transport minister to make sure the rail infrastructure firm consults properly on felling plans.
The Royal Society for the Protection of Birds says up to 1.5 million nests are at risk of being destroyed by the work.
Network Rail says cutting down trees to ensure safety and avoid delays is cheaper than repeatedly pruning them.
The firm has removed trees from hundreds of miles of its tracks up and down the country in recent years.
Network Rail, which maintains 20,000 miles of track, says trees can obscure signals and weaken embankments, while leaves falling on the line can cause delays.
But residents complain the removal of the trees exposes gardens to railway lines.
Mr Corbyn wants transport minister Teresa Villiers to make sure Network Rail consults properly and is prevented from felling trees during the nesting season.
"Clearly, moving trees away that are very near to signalling equipment and the line, that is necessary," Mr Corbyn told BBC News. "I understand and accept that.
"But the management of the vegetation alongside a track is part and parcel of railway management and they should just accept that and factor it into their budget."
MPs are to debate the issue later on Wednesday in Parliament's Westminster Hall.
Environmentalists say removing trees from railway embankments across the country is the equivalent of destroying an area as large as the Forest of Dean in Gloucestershire.
John Fletcher, of Dronfield Civic Society in Derbyshire, told BBC Radio 4's Today programme: "This is more than just a hedge-clipping experience, this is where Network Rail has gone and taken out complete swathes [of trees] throughout the town."
The company had cut back vegetation up to 90ft (27m) from the track without properly informing residents about the scale of the work, he added. And it had "impacted upon the entire vista" of Dronfield.
Darren Moorcroft, of the Royal Society for the Protection of Birds (RSPB), accused Network Rail of breaking the law - a claim the company denies.
All wild birds, eggs and nests are protected by law and the destruction of nests during the nesting season between March and August is generally considered to be a criminal act, according to the RSPB.
Mr Moorcroft said: "In some places we have informed the police who have come along and stopped [Network Rail carrying out the work]."
One of the places the RSPB intervened was in Whitstable, Kent, where residents had chained themselves to trees to prevent them being felled.
Robin Gisby, Network Rail managing director of network operations, admitted his company had been "clumsy" with its tree-felling work in some areas and said it would seek to put this right.
But the maintenance was essential to ensuring safety on the railway and in some cases residents had requested the company cut back more trees than it had, he added.
"We clearly do not just want to abide by the law," he said, "but by the spirit of working with our line-side neighbours.
"We are just trying to achieve a balance here."
Mr Gisby added Network Rail was "by no means anti-tree", had planted a large number of trees along its track and tried to carry out tree felling outside the nesting season.
Rail Minister Theresa Villiers said the matter was an "operational issue" for Network Rail.
However, she said she had emphasised to the firm "the importance of striking the right balance between providing a safe, reliable and affordable rail network and meeting concerns about the natural environment and the quality of life benefits line-side trees and vegetation can provide to local communities."