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Will there ever be a tunnel connecting England and Ireland?

It’s been talked about – a lot. It could boost business and tourism, and a major infrastructure project could be a big boon to the economy at the moment. It would be one of the longest bridges or tunnels in the world – up there with some of the biggest Chinese bridges. But it’s certainly possible.

The problem is geography.

Where does it start and end? There are four proposals out there already:

None of these are perfect.

Campbeltown to Antrim is the shortest, so most feasible. But Campbeltown is at the tip of the Mull of Kintyre – it’s an isolated part of Scotland, and significant work would need to be done to improve the transport links there.

Stranraer to Belfast is similar: big plus for connecting directly with Belfast and for being an achievable distance – about 20 miles. It was proposed in 2007 as a part tunnel / part bridge. But Stranraer is also isolated and it would require significant investment. It’s hard to see who the target market on the British side is.

Dublin to Holyhead is similar but more financially viable: very big plus for connecting Dublin directly, and Holyhead is a rail hop to Manchester, Liverpool and the North. But it’s 50 miles long – that’s some serious work – and the business case probably isn’t quite there. It would almost certainly have to be rail only at that distance – they are much smaller than road tunnels and don’t have the same ventilation requirements.

And Rosslare to Fishguard is a tough sell – at 45 miles it’s similar to the Dublin route, and could connect with Cardiff, Bristol and the south of England. This time the investment would be needed in Ireland to make it worthwhile. It would also be much more beneficial to Ireland, which would gain a near-direct route into Europe, than to the UK, and the balance of benefits makes it unlikely.