The UK government’s decision to go ahead with the first stage of HS2 — a high-speed rail network that would ultimately link Scotland to southern England and the midlands at 400km/h — poses some hard questions for those for and against high-speed rail in Australia.

For those in favour of a similar route structure in on the eastern seaboard, linking Melbourne to Sydney and possibly Canberra, the question that shouts from the page is how come the UK is working on a $49 billion bill (at current dollars and exchange rate) for a project that we publicly argue as costing more than $100 billion, yet with land prices and engineering challenges that are lower than those of the densely populated Midlands landscape?

The answer may be that the UK is not falling for excessive financial engineering, which plagues Australian infrastructure costs and represents a severe failing of political acumen on both sides of the house.

The great infrastructure rip-offs apparent in the likes of the Sydney cross-city tunnel or proposed metro train lines and heavy rail projects in Sydney have to come to an end before anything gets done. Do we really have to cost projects in this country at two or three times the cost in Europe or the UK, when direct public borrowing can deliver cheaper tolls, more customers and faster repayment of capital expenditure?

On the opposing side a much more difficult question arises, even for the Greens, who support high-speed rail.

The UK papers today are  full of images of pony riders, ancient forests and beautiful Tudor towns, all destined to be destroyed/overshadowed/acoustically r-ped or otherwise compromised by stage one of HS2, which will connect London Euston to Birmingham in 14 years and slice station-station trip times from 90 minutes to 49 minutes.

The image below, widely used on HS2 protest social media, is in The Daily Telegraph this morning, and the caption captures significant public disquiet over the project …

This is the problem. The Greens make themselves a party in favour of cutting-edge technology (good) but cannot escape from the reality that any conceivably achievable Sydney-Melbourne, or even Sydney-Canberra, high-speed rail route will have devastating environmental consequences, for wildlife, for species diversity, and for wilderness per se by carving a permanent way, with extensive blast and acoustic shielding near and through towns, especially as the economics will require multiple regional services as well as non-stop expresses.

It is easy in any shade of Australian politics to say stirring things about infrastructure projects, but the realities of financing them, and confronting the environmental impacts, are very tough.

High-speed rail is a debate Australia has to have. It is a technology we have to apply. But getting there will be ugly, brutal and divisive, as HS2 in the UK is demonstrating today.