Those who voted for Brexit and those who now accept it are united by one positive thought – this could be a potential catalyst for national renewal, a kick in backside for the Establishment, in order to encourage it to do things it should have been doing anyway.

It follows that one of the reasons Brexit is going badly is that the opposite has happened. Instead of nation building, we are navel gazing. At some point, we are going to have to pull ourselves together and get on with it.

The money men in the Treasury are mostly to blame. I don’t know what they get up to on any given day. One assumes it is mostly corridor cricket and coming up with ruses to delay Brexit. The only memorable measure in the last Budget was a plan to withdraw the one penny coin, itself dropped 48hrs later. The situation in No10 has been described as the ‘May Celeste’. And across Whitehall the civil servants are, one expects, planning an entire 6 weeks of working from home to coincide with the World Cup.

So here is an idea to give the country a happy pill: how about building a bridge between Northern Ireland and the mainland? It would kick start economic growth, enthuse the DUP, support the Union, bring the country together and create a stability to Brexit which not even the EU could knock-off balance.

There is, in fact, a precedent, as I learnt recently from Julian Glover’s excellent biography of the engineer Thomas Telford. When the Irish and English Parliaments were unified in 1801, Telford was commissioned to make travel between Dublin and London easier and this resulted in his wonderful Menai Straits Bridge and the Holyhead Road.

A Scottish/Irish bridge is not my idea – I first had my attention drawn to it by a Cabinet Minister. It is the idea of a Scottish architect, Professor Alan Dunlop of Liverpool University, who gained some attention for it in January after Boris Johnson said we should build a bridge across the English Channel.

Mr Dunlop says that the shortest route – 14 miles – is from a fishing village called Portpatrick on the West coast of Scotland, in Dumfries and Galloway (the constituency of Alistair Jack, one of Scotland’s seven Conservative MPs), to Larne or Bangor on the Northern Irish coast. His back of the envelope calculation is that this would cost £15 billion (about a tenth of the cost of a Channel bridge).

Before the under-arm bowlers in the Treasury say: “We can’t afford that”, consider that such a bridge would likely charge tolls. The Severn Crossings in South Wales charge (or used to before they went into public ownership a few months ago) £6.70 for cars and £20 for lorries. In 2016, the 14.5m vehicles using the bridges paid £103m in tolls.

A better example comes from the brilliant Øresund bridge linking Copenhagen and Sweden. This charges around £150 for lorries and £30 for cars. As the stunning bridge has been economically transformative for the area – traffic has doubled since it was opened in 2000 to around 19,000 vehicles a day, plus trains – these tolls are happily paid by users. Last year, the bridge had revenue of some £430m and was profitable, even after accounting to interest and finance costs.

One has to concede that connecting a Scottish fishing village with an Irish one is unlikely to be anything like as economically compelling as the benefits of linking the great conurbation of Copenhagen with its Swedish neighbour (soon to be further enhanced by a tunnel to Germany), but a bit of imagination suggests that unlike Boris’s bridge across the channel, a Scottish/Irish link ought to be financeable without breaking the backs of the UK, Scottish or Northern Irish taxpayers (ok just the English, we will end up paying as usual). The tolls could probably sustain at least £5bn of debt.

The idea has already won some political support. It was in the DUP’s election manifesto and Mike Russell, Scotland’s Brexit minister, supports it. The Scottish government has said it will look at it. Uncharacteristically, Ruth Davidson has been quiet on the subject.

One issue which will have to be overcome is a deepwater gully in the sea called the Beaufort trench which the Royal Navy have apparently been cheerfully dumping unused ordinance into for decades. Furthermore,  considerable road investment would be required, to connect Portpatrick to Glasgow, the central belt and to Carlisle and the M6. It doesn’t have a rail station. And the Department of Transport has not only blown the budget on HS2, it seems incapable of executing major projects (witness its bungling of the new rail timetable).

Perhaps the biggest obstacle though is psychological. Too many people, especially in Westminster and the media, have been reduced to jelly by the prospect of Brexit. Ironically, a big bold project like this would be the perfect cure. It is a cause the Government in London should take up.