LONG-DISCUSSED improvements to the Cotswold Line have been thrown into doubt after a Government minister questioned a similar upgrade to a neighbouring rail route.

Plans to reinstate a second track on the line between Oxford and Charlbury were backed last year by Witney MP and Prime Minister David Cameron.

He wrote to Chancellor George Osborne and Transport Secretary Patrick McLoughlin calling for funding to be committed before the end of the last Parliament.

But plans for similar railway improvements between Honeybourne, on the Cotswold Line in Worcestershire, and Stratford-upon-Avon, have been dismissed by transport minister Clare Perry as having no strategic value.

Her statement has worried campaigners, who have now demanded Mr Cameron reaffirms the Government’s commitment to the Oxford to Charlbury improvements.

Mr Cameron’s intervention came after the number of passengers using the Cotswold Line more than trebled, with local people saying improving the line would ease commuter pressure on the A40.

Witney county councillor Laura Price said: “It’s something that people have been talking about around here for years, but haven’t got any traction with.

“Then last year county council leader Ian Hudspeth started getting a positive response when he was talking about it and Mr Cameron weighed in with his support.

“There will be serious questions if this now drops off the agenda.

“People want to move to West Oxfordshire because of its good commuter links.

"But when they actually get here they see it is choked with congestion.”

Quoted in an article in Railnews magazine, Ms Perry said doubling 17km of the Cotswold Line between Charlbury and Wolvercote, Oxford, would cost £160m to £200m.

She added that this work would have to be completed before an adjoining route linking Honeybourne and Stratford could be built.

Referring to that adjoining route she said: “There is no strategic case for this to be done.”

The numbers of passengers using Hanborough Station on the Cotswold Line has almost trebled from 76,000 in 2004/05 to 201,000 in 2013/14.

Campaigners argue motorists use it as a way of avoiding the crowded A40, the main route between Oxford and Witney, by turning off on the A4095 and leaving their cars at Hanborough before catching the train into Oxford.

The car park at Hanborough Station has been expanded in recent years to cope with demand, but is now filling up and services on the line are limited to one per hour because of the single track sections.

Transport campaigner Hugh Jaeger said: “If there’s been a U-turn on doubling the Cotswold Line Mr Cameron needs to step up and say what’s happening.

“I think it’s short-sighted. The number of passengers has increased more than the service simply because of people taking the initiative and deciding the A40 is choked.”

A Department for Transport spokeswoman said it was still considering plans for the Cotswold Line.

She said: “We are working closely with Network Rail and First Great Western to look at how the railway could be improved to give passengers on the North Cotswold line faster and more frequent services.

“This includes the potential re-doubling of the route between Oxford and Worcester, incorporating Charlbury to Wolvercote.”

Network Rail completed the redoubling of 20 miles of track from just east of Charlbury to Ascott-under-Wychwood, and from Moreton-in-Marsh to about one mile west of Evesham in 2011.

David Cameron’s office did not respond to requests for comment on the issue.