FAILURE to go ahead with the HS2 rail link would lead to 14 years of weekend closures while existing lines were upgraded to provide the additional capacity, according to a Government-backed study.

A report prepared by Network Rail and management consultancy Atkins has concluded that there would have to be 2,770 weekend closures - totalling 144,000 hours of work - on the East Coast, West Coast and Midland main lines if it was to replace the intended capacity of HS2.

The study, which will be published tomorrow as part of the Government's strategic business case for HS2, warns that, during a typical weekend, the journey time from London to Leeds could more than double from two hours 10 minutes to more than four and a half hours.

The Guardian quotes the report as saying: "Network Rail's judgment is that the scale of service closures involved across three main lines makes the alternatives very unattractive.

"While some works could be programmed to coincide in terms of network downtime, this scale of work on the existing network would entail 14 years of weekend closures to allow the necessary upgrade works to be carried out.

"With work on multiple (parallel) routes, the scope to use adjacent main lines for diversionary routes is also diminished."

Robin Gisby, Network Rail's managing director of network operations, said that any attempt to upgrade existing lines would inevitably lead to "very heavy disruption" to services.

"We saw that with the upgrade of the West Coast over the last decade," he told the BBC Radio 4 Today programme.

"If you think of the route from London through the Channel Tunnel, that used to go into Waterloo - supposing we had upgraded the line from Waterloo all the way through the middle of London commuting out to the Channel Tunnel instead of building High Speed 1 - it would have been very difficult.

"I think the same applies north of London. What we need is more fresh capacity. Doing that by cannabalising some of the existing routes doesn't give you give you the long-term balance and causes considerable disruption in the meantime."

The disclosure comes at the start of a crucial week for HS2 when the Government may need Labour support in the Commons as a number of Tory MPs are preparing to rebel and vote against a Bill paving the way for the project.

Transport minister Robert Goodwill said the Network Rail-Atkins study made clear that upgrading existing lines was a non-starter - despite costing less than half the projected £42 billion cost of HS2.

"Spending £20 billion on upgrading the existing network isn't an alternative. The disruption that would be caused would be a nightmare. This report makes that absolutely clear," he told the Today programme.

"It would only give us a third of the additional capacity which would mean that we would not be able to put more freight on the rail, we would not be able to put additional services into intermediate stations."

© Press Association 2013