Reeves must guarantee HS2 runs to Euston, spending cuts or not

No, the long and painful saga of HS2 did not reach its final destination when Rishi Sunak axed the entire northern phase of the project last October. For starters, there is the mopping-up exercise on the cost of that decision – a write-off of £2.17bn in the latest accounts .

Of that, £1.1bn is money actually spent on the ground in preparing phase two before it was jettisoned. It is money down the drain in the purest sense.

But then there is the unresolved question of Euston, which has been its own fiasco within the greater shambles.

The intended HS2 station on the site has been through two designs already and there is still nothing resembling a final plan, in large part because the Department for Transport “still does not know what it is trying to achieve”, as the public accounts committee put it in July last year .

The former prime minister’s last contribution was to ditch the 10-platform version and appoint a new development body to attract private capital and develop a definitive strategy.

On the plus side, Sunak’s action did at least seem to acknowledge that it would be absurd to stop the railway at Old Oak Common , five miles to the west of Euston. All the modelling shows the destination would primarily be convenient only to about a third of passengers – those going on to Heathrow or catching the tube network’s Elizabeth line.

On the downside, the outgoing government did not actually provide the funding to set the tunnelling machines in motion to complete the last leg to Euston.

Related: HS2 reveals £2bn in costs linked to Sunak’s downgrade of line

It is why the forward-looking detail on page 48 of HS2’s annual report, as opposed to the historical write-offs, was the critical bit of the document: “Failure to secure funding to deliver Euston tunnels and station could impact the organisation’s ability to safely operate and maintain Old Oak Common Station and train services across HS2, Great Western Main Line and Elizabeth line.”

Well, quite. Stopping at Old Oak Common would probably overwhelm the already heavily-used Elizabeth line and make the whole system less resilient.

Many west coast passengers would probably continue to use the conventional service to Euston, thereby undermining the supposedly core idea that HS2 will release capacity for local services.

In short, there is no alternative to going onto Euston. HS2, even in its slimmed-down incarnation, makes little sense without it.

Despite speculation that the future of the Euston tunnel hangs in the balance, the chancellor, Rachel Reeves, did not mention it in her list of spending cuts on Monday.

Let us hope that means the money will arrive from somewhere because a critical point is fast approaching. The boring machines, awaiting final assembly in Germany, need to be dropped into place at Old Oak Common before the next stage of work on the station, due to be completed between 2029 and 2033, proceeds.

The actual design of Euston can wait a while, but a green light for tunnelling is required within months.

The overspend on the misconceived HS2 over the years has been a national embarrassment . But phase one without the leg to Euston would make a bad situation worse. Reeves should clear up the fresh uncertainty over the tunnel. It has to be built.