Campaigners near Pontypridd want to save a historic railway footbridge from demolition.
They say the Smokey Bridge, in Hopkinstown, is a vital part of the area's industrial heritage.
The bridge, built to help miners cross the railway line, has been closed since 2014.
Both Network Rail and Rhondda Cynon Taf Council have responsibility for the structure.
The council proposes an 'extinguishment order' for the footpath, a major step towards proceeding with the dismantling of the bridge.
It says the bridge is in "very poor condition structurally".
Campaigners say the bridge is a rare surviving reminder of the area's coal industry.
The nearby Tymawr Colliery closed in 1983, with the site cleared and turned into a housing estate.
The Grade-1 listed Hetty Pit winding house and headgear survives.
Network Rail says it "must balance the needs of those who are keen to retain various historical assets with our responsibility to provide a safe network, with the best value for money to the taxpayer."
The deadline for people to oppose the extinguishment order is August 25.
The campaigners now hope historic environment body Cadw will consider listing the structure.
Cadw confirmed to ITV Wales that it had been asked to look at listing the footbridge.
A spokesperson said it is "currently in the process of considering the request".