The group who want to restore it say it doesn't make financial sense to abandon it.
It would be cheaper to drive a new Queensbury Tunnel than repair the existing one at the price put forward by the body that looks after it.
That’s one of the findings contained in a study of tunnelling costs published by the Queensbury Tunnel Society (QTS) which is campaigning for the historic structure to be restored so that it can become the centrepiece of a cycle path network connecting Bradford, Halifax and Keighley.
The group statement said: "The future of the disused railway tunnel is currently under threat because of abandonment plans being progressed by Highways England’s Historical Railways Estate (HRE) which examines and maintains it on behalf of the Department for Transport (DfT).
"Last year Jacobs, HRE’s consulting engineers, produced a report on future asset management options for the tunnel which put the cost of abandonment at about £3 million, compared with £35.4 million for repair."
"Subsequently, a review of Jacobs’ report by specialist tunnel engineers found a number of basic and substantive errors, as a result of which the Society asked the Department for Transport to prevent any further abandonment work being carried out until a full and robust examination of options for the tunnel has been undertaken. The DfT has not responded to that request; neither has it made any comment on the “pragmatic and proportionate” remediation scheme - costed at £2.81 million - put forward by the same specialist tunnel engineers."
Norah McWilliam, who leads the Queensbury Tunnel Society, said: “Having ruled out repair on the basis of a deficient report with questionable costings, the Department for Transport now seems to have pulled the shutters down, refusing to even acknowledge a robust repair plan developed by a specialist engineering team which demonstrates that the tunnel could be made safe for public use at a price comparable with abandonment. Our new study provides clear insight into just how inflated that initial costing was. Why did HRE not recognise that? They have serious questions to answer about Jacobs’ report, the process that resulted in it being accepted and their subsequent use of it.”