On Brexit, will no one in the major parties admit that Britain has blundered?

Polling suggests Keir Starmer would still win even in red wall seats if he declared Brexit to be a mistake. Photograph: Ian Forsyth/Getty Images

‘Half a league, half a league, / Half a league onward. / All in the valley of Death, / Rode the six hundred.” Why does Tennyson’s great poem come to mind as the local garage waits for a spare part to be delivered from Turin to fix a problem with my Fiat?

In pre-Brexit days, thanks to Margaret Thatcher’s great achievement in integrating the British economy into the European single market, spare parts for cars, dishwashers – you name it – could be delivered almost overnight thanks to the sophistication of the EU supply chain.