As we reported yesterday, Prime Minister David Cameron announced the plan, known as HS2, to plough a Y-shape fast track from Birmingham to Manchester and Leeds by 2033, with trains travelling at up to 250mph.
This will shave journey times from Scotland to London and Birmingham, with a trip to London from Glasgow taking 3hrs 30min.
But city leaders say such marginal benefits will pale in comparison to the huge competitive advantage cities in northern England will have over Glasgow and Edinburgh within two decades.
Scotland's two big cities instantly protested there were still no firm plans to extend the high- speed line north of the border.
Glasgow City Council leader Gordon Matheson welcomed the HS2 line as opening up "fantastic opportunities and growth for the UK". But he added: "I have long argued that Scotland's two largest cities must be included in this network.
"It is essential construction of a high-speed rail route begins at both ends of the country and meets in the middle.
"If it doesn't then I believe our people and economy will be the losers – cut off from our major markets in England and Europe and at a huge economic disadvantage."
The "middle" is, in fact, Manchester and Leeds, which are routinely referred to by London administrators as "northern cities", despite being in the southern half of Great Britain.
Mr Matheson's concerns are widely shared in Glasgow.
HS2 will cut the time it takes to get from London to Manchester to under an hour. Suddenly, the northwest of England – already desperately trying to fight Glasgow and Edinburgh for highly lucrative business, such as conferences and events – has a huge competitive advantage.
The Scottish and UK Governments and their transport officials are talking about taking the line north. But there is still no agreement over who would pay for such a scheme, already dubbed "phase 3".
In theory, the UK Government would be expected to pick up the bill for tracks laid all the way up to the Scottish border. But there is probably no economic case for a high-speed line to link Cumbria to the rest of England. So will the Scottish Government pitch in to pay for track in England?
Scottish Transport Minister Keith Brown insisted UK Transport Minister Simon Burns was offering reassurances Scotland would figure in high-speed plans.
The big green and financial pluses of high-speed rail only really kick in if the tracks go all the way to Glasgow and Edinburgh, suddenly shifting high-spending frequent flyers out of the cities' airports and into stations.
Mr Brown said: "The full benefits of this project can only be realised if Scotland is involved and it looks like Westminster has finally taken note.
"The Department For Transport has "warmly welcomed" our enthusiasm for high-speed rail and our recent announcement we will push ahead with planning for a high-speed line between Edinburgh and Glasgow.
"I pointed out to Simon Burns that – as a rail funding authority – it is vital the Scottish Government has a lead role in that process alongside DfT."
Mr Brown's SNP colleague Gordon MacDonald took a tougher line. The MSP said: "Why does the Tory-led Westminster system want to keep Scotland in the slow lane?
"There is an undeniable economic case to connect Scotland to the rest of the UK and the Continent.
"It's welcome that they now recognise Scotland is essential for the success of High-Speed Rail, but Westminster has dragged its heels on high speed rail for too long."
Shadow Scots Secretary Margaret Curran said governments in Edinburgh and London had nothing to show for two years of joint work on so-called "Phase 3".
She added: "The UK Government's case for High-Speed 2 identifies the economic benefits that will come from this line. The UK and Scottish Governments need to get to grips with this to make sure a plan is in place to take high-speed rail all the way to Scotland."
Liz Cameron, chief executive of the Scottish Chambers Of Commerce, also warned Scotland could be marginalised if Phase 3 was not completed quickly.
She said: "While marginal benefits will accrue to Scotland in terms of slightly shorter journey times if the 'Y' network is completed on schedule in 2033, the Department for Transport's own figures show that central Edinburgh to central London journeys will still be quicker by air than by rail two decades from now.
"There is pressure on Scottish air links to London because of capacity problems at Heathrow and HS2 will deliver significant connection benefits for English cities, so this could lead to Scotland becoming even more marginalised in relative terms.
"By 2033, Manchester-London journey times could be reduced by 47%, whereas Glasgow- London times would fall by about 12%, meaning the benefits of High-Speed Rail in the absence of a true UK network disproportionately favour English cities."
Green Party MSP Patrick Harvie said: "If one of the main purposes of High-Speed Rail is to reduce the need to fly then it is the longer journeys between Scotland and London that will make the real difference."