Before Scotland's referendum, we heard now and then that HS2, the high-speed rail link, would be among the benefits of Union put in peril if there was a vote for independence.

The vote was No. Afterwards, we were not left in suspense, if you can call it suspense, for too long.

If reports at the weekend were right, it's not coming. Even the old, vague story of "perhaps in 30 years" has given way to a claim, attributed to HS2 Ltd, that there is no business case for running a line deemed essential to the economy of one part of the United Kingdom to any other parts. All that remains to be heard is the answer to a question: whose business case?

Those who live around the quaint branch lines in Scotland, Wales or the north of England will still pay their share for a very expensive piece of infrastructure, of course. That, you will be reminded, is just how the UK works. According to one of the campaign groups attempting to halt the project, Scotland's share will be £3.64 billion. Trains reducing the journey time between London and Birmingham are, says the Government, for the benefit of all.

You need not be a Scot to raise an eyebrow at that. The Welsh, cut out of the loop physically, will pay for HS2. Northern Ireland, geographically apart to begin with, will contribute too. Three regions in the north of England, wondering again where the internal borders of the UK actually lie, will hand over their share and wonder about perspectives.

In addition to its gargantuan costs - £50bn, but keep your eye on the clock - HS2 was supposed to be one of those symbolic projects. Lord Adonis, the sort of person who retains influence within Labour without ever troubling the electorate, spoke last year of a "Union railway", binding all together. The English north meanwhile heard about old divides being closed. This week, it is hard to find anyone prepared to guess when, or if , the new line will even reach Manchester.

Scotland, devolved or independent, has particular interests in transport matters. The English south is both a destination and an obstacle should you want to travel, work, or trade, by road or rail. Reaching Europe is, let's say, a challenge. Air links are about as much fun as a quick spin around the M25. Here, as in Wales or on Tyneside, equal rights in a rail network are not matters of chauvinism. Infrastructure investment meanwhile matters hugely when there is a UK Chancellor with nothing else - nothing at all - to offer.

You could make a purely Scottish case easily enough. The biggest project here is the Forth Replacement Crossing, the new bridge. As things stand, it will be ready for 2016 at £1.45bn, £145 million less than previously estimated. The contrast with the £3.46bn figure, thus far, for Scotland's subvention to HS2 is obvious. But this argument is not a simple dispute over whose turn it is to win a share of those "pooled and shared" resources. It applies to all who do not reside in southern England.

There was, for example, a £9bn Olympic Games in the great city of London. That was "for the benefit of the whole UK", but not as a cash benefit. It was as nothing, in any case, to the £14.5bn spend planned, when last we heard, for London's Crossrail. Schemes to bring the Tube up to scratch will meanwhile cost £8.2bn. Scotland's complaints have a precise political and economic context, but there is no part of the UK outside the English south east without - what's that Unionist word? - a grievance.

The story isn't new. The London Government's 2013 infrastructure plan caused much haggling last year among think tanks and civil servants. The most conservative interpretation, applied to England alone, is that the country's capital gets double the amount of transport infrastructure spending per head than any other English region. Is Newcastle OK with that?

But perhaps London and its multitudes of consumers need the investment. Perhaps, despite all George Osborne's talk of northern powerhouses, all of this is mere recognition of economic reality. London makes money; London cannot be allowed to falter. Is Manchester happy with that? Have its people got the hang of the pooling and sharing thing? England's capital grows ever-richer, but for the general good. Someone in London said it, so it must be true.

There's a question for the UK in that. When does this general good come to be experienced, far less understood? Mr Osborne has come to a belated understanding of the need, as he describes it, to rebalance the economy. Some £15bn, from various sources, has been mentioned for the English north-west and that powerhouse. It's unprecedented, they say. It's a whole Crossrail, give or take. And still it isn't even half of what is planned in total for London's infrastructure.

How does that happen? Northumbrian patriots, like Scottish nationalists, would tell you it was ever thus. London think-tankers will meantime give you the run-around with arguments over the differences between public and private investment. The question of choices remains. Who makes them and why? Who decides - for there is no version of the numbers that says otherwise - that London must come first? In this debate, Scotland isn't even at the front of the queue.

HS2 is authentically symbolic. The line will not reach here. The modern world will not extend to the northern provinces, Scottish or English. As many have observed, you could spend £50bn and improve the rail network for everyone in the UK, but according to the tale given to the Independent on Sunday at the weekend, there is no "business case" for that. It is equivalent to saying there is no business case for Glasgow or Gateshead.

Stewards of the Union need to think this through. A substantial number of Scottish voters regard matters such as HS2 as, in essence, the usual. They recognise a bit of referendum propaganda as a lie. There never was a serious intention to develop a line that would connect Glasgow, Edinburgh, Dundee and Aberdeen with a high-speed network. English people in their north-before-the-north might meanwhile be getting the hang of things. Manchester/Leeds counts as the outer limits.

There are no serious plans for Wales; nothing for Newcastle; nothing for anyone in suddenly invertebrate communities lost without the spine of a "business case". And nothing, say the reports, in this generation or the next, for Scotland. I'm not even slightly surprised. Despite all their political scares, despite a general election result, the London political class struggles to glimpse much beyond Birmingham New Street.

For Newcastle, as for Dundee, the pressing case is simple. If the UK functions as advertised, why is Crossrail an essential project, one decided and funded without real argument over the vast sums at stake, and why is every other city at the whim of decisions made in London's interest?

For now, the nations and regions of the UK are being charged for the privilege of hearing why they don't matter. That's someone's one-way ticket.