Supporters, who have been campaigning for a commuter link from Okehampton to Exeter for 14 years, say it is now time for Network Rail to think seriously about the cross country route.
Trains can already run to Meldon, west of Okehampton, on a freight line and there are currently plans to re-open a stretch of line connecting Tavistock to the Tamar Valley Line at Bere Alston which goes through to Plymouth.
MPs are calling for urgent debate on the issue and the current crisis has highlighted the need for action.
Damage to the track at Dawlish in the recent storms means that the line between Exeter St Davids and Newton Abbot is not expected to re-open until mid April at the earliest.
Geoffrey Cox, MP for West Devon, said it was simply not acceptable in this day and age that areas of the South West should be completely cut off by both rail and air.
'I have already made it clear to the Transport Secretary that urgent action is essential,' he said.
'I will reiterate that and also stress that transport links to this area should be restored as soon as possible and that alternatives should be looked at to ensure this does not happen again.'
Network Rail said no firm decision had been made on an alternative route and the priority was to resume rail services to Devon and Cornwall as soon as possible.
'We will take forward a professional study on this once the current situation is resolved, engaging business, local authorities, communities and the rail industry in the advantages and disadvantages of alternative routes,' said a spokeswoman.
The Plymouth to Exeter line via Okehampton was closed in the 1960s and the land sold off and built on.
Network Rail said it would require substantial engineering, including new bridges and viaducts, before a new line could be constructed.
The two other alternative routes that are being considered are in South Devon.
Transport Secretary Patrick McLoughlin has said that all options remained on the table and he would enter into the debate once the study was completed.
Author of the Great Railway Conspiracy, David Renshaw, said overall, a new cross country line linking Plymouth, Tavistock, Okehampton and Exeter of more than 50 miles in length was a viable option.
Meldon to Tavistock via the proposed Okehampton Parkway and Lydford Gorge Parkway stations had had its track removed — but the trackbed was almost entirely intact and could be reopened, he said.
'In Tavistock itself lies the only barrier; one or two houses and the West Devon Borough Council offices,' he said.
'These do not need to be entirely demolished, but some work would be needed to route the railway through here.
'Exeter-Okehampton-Plymouth would be much easier and cheaper to do than the technically complex task underway in Scotland — the Borders railway linking Edinburgh with Galashiels and Tweedbank, which is only 30 miles long and will cost nearly £300-million,' said Mr Renshaw.
'Journey time would actually be faster than the existing route via Dawlish, which is hillier, twistier and more prone to poor weather issues.
'My suggestion is to re-open the northern route as a secondary line, rather than replacing the Dawlish line, but many faster trains would run that way, some stopping at Okehampton, and it would take over in bad weather.'
John Love, a former director of the Dartmoor Railway, who presented his case for the restoration of the Exeter to Okehampton line at a public meeting at the Fox and Hounds in Bridestowe on Tuesday night, said there was an awful lot of support for the route.
'The momentum is there because of what has happened at Dawlish and it is important we keep that going.
'There are a lot of mountains to climb and it could be many years before the project comes to fruition but I am confident it is feasible.
'A tremendous amount of work has been done to prove that it is.'
Kilbride Rail has set up the Bere Alston to Tavistock rail project, the go-ahead for which will be conditional on a housing development for 750 homes being approved in the town.
Managing director Peter Frost said: 'A number of critical decisions are being made in the next few weeks and it is vital all parties continue to work closely together to move the Bere Alston to Tavistock project on as quickly as possible.'