Campaigners fighting to preserve historic Greenside Tunnel hope the presence of bats could be a major weapon in their opposition to a potential residential development.
Members of the Save Greenside Tunnel campaign fear developers will fill the former railway cutting, sealing the tunnel and burying part of the local landmark which dates back to 1893.
They also say the work would destroy a green corridor which is home to local wildlife and history.
Developer EP Homes, which has built properties on the nearby Fartown site, has yet to make a planning application to build on the site.
Campaigners say bats roost in the tunnel and are asking any local residents to log any sitings.
Local resident Charlotte Hobson has been in contact with the national Bat Conservation Trust and said:
“The more evidence we have of bats, the more it will contribute to the opposition to any planning application. The bats will just be starting to come out of hibernation now and I know there’s a roost there.
“There’s a lot of opposition. I just want it to be left as it is, a fantastic wildlife haven.”
John Cliff, from EP Homes, told The Dispatch he was ‘absolutely conscious’ of the fact that there were bats on the site. He added:
“There has been no planning application put in yet. We do want to develop the site but we are still conducting surveys and I can’t say any more at present.”
Mr Cliff said it could be ‘the end of the year’ when all the surveys are completed on the land, which has been subject to flytipping in the past.
As previously reported, EP Homes wrote to local residents last year in an effort to keep them informed of developments.
Councillor Mick Coulson (Lab, Pudsey) said Pudsey ward members had been opposed to different proposals for the site over the past 12 years.