A REVISED report on the business case of extending HS2 to Scotland will be ready "early in 2016", a transport conference has heard.

Keith Brown, Cabinet Secretary for Infrastructure, pressed the company responsible for developing the UK's high-speed rail line to reconsider its earlier conclusions that there was "no business case" for HS2 to continue north to Glasgow and Edinburgh.

Mr Brown told an Anglo-Scottish high-speed rail conference in Glasgow that expected to receive the findings of the new HS2 Ltd study early next year, and stressed that it was vital that high-speed rail extended north of the Border in order to achieve Scotland-London rail journey times of less than three hours, which is key to encouraging a modal shift from air to rail.

He said: "It's crucial not just for Scotland but for the north of England, and for a vibrant and inclusive economy for the whole of Britain.

"Failing to extend HS2 into the north of England and Scotland would arguably be more detrimental to Britain than bit having high-speed rail at all because of the inequalities it would create."

Mr Brown added that he had been impressed by the ambitious super-fast rail development by Russia and China, which is set to connect the two capitals within a decade.

"Russia and China will build a high-speed rail link between Moscow and Beijing in 10 years. With HS2, we're talking 25 years.

"I found it hard to understand why we are taking that long, although I know we are dealing with very different labour costs and environmental conditions there compared to here.

"But that development will cut the travelling time from Moscow to Beijing from five days to 30 hours. That's real ambition.

"We only want to reduce the travelling time from Scotland to London from four and a half hours to less than three."

On current projections, the journey time from the Central Belt to London will be reduced to 3 hours 38 minutes once Phase Two of HS2 - linking the high-speed lines to Manchester and Leeds - is completed in 2032.

However, members of HS2 Ltd told the conference that current proposals to extend Phase One beyond Birmingham to Crewe would mean Scottish passengers "wouldn't be far off" a 3 hour 38 minute travel time by around 2026.

Duncan Sutherland, director at HS2 Ltd, said: "If we get to Crewe I don't think it'll be that much different because you can see how far up Crewe is on the West Coast Main Line."