Transport secretary Ruth Kelly last week moved to quell the dispute between rail engineers and National Grid over a disused South Yorkshire rail tunnel.
National Grid wants to install a new set of cables in the disused 4.5km double track Woodhead rail tunnel, which runs between Sheffield and Deepcar (News last week).
But, rail campaigners including Network Rail chief executive Iain Coucher claim the tunnel needs safeguarding so it can be used by freight services. They have warned that the cabling would create an irrevocable loss of rail capacity.
But Kelly was unable to say whether track could be re-laid without additional intervention by National Grid, or National Grid's cables are being relocated from two disused single bore Victorian rail tunnels nearby. The Save the Woodhead Tunnel campaign claims that National Grid could refurbish these tunnels and run the replacement cables through them instead.
National Grid claims that refurbishing the Victorian tunnels would cost a prohibitive £165M. But campaigners have rubbished the figure as wildly exaggerated.
Civil engineer and the Save the Woodhead Tunnel campaign spokesman Alan Shaw said that if National Grid does lay the cables, the Woodhead tunnel rail line could only be re-laid after a significant amount of civils work.
"If (for argument's sake) National Grid were to try to install the cables and then a railway above them it would reduce the loading gauge for the railway and make the cables inaccessible for maintenance.
"National Grid would be left needing to take possession of the tunnel to effect repairs which may involve removing track and disrupting trains," he said.
During the select committee meeting Kelly admitted that she wanted some disused rail routes to be protected, as future demand is unknown.
She told MPs on the committee that the Woodhead tunnel might be one of these.
"It may well be the case that if demand continues or exceeds current growth we may need more provision for rail on that particular corridor," she said.