Xjyuk

According to Channel 4:

The DUP, the party supporting the Conservatives in Parliament, believes a bridge [between Scotland and Northern Ireland] could break the Brexit impasse by removing the need for a border in the Irish Sea.

Is there an explanation of how building such a bridge would remove any need for a border in the Irish sea?

The "border in the Irish Sea" refers to a regulatory border, namely a customs border, that would require customs inspections of vehicles traveling between Northern Ireland and rest of the United Kingdom. More specifically, it refers to a plan to have Northern Ireland be a separate customs territory from the rest of the UK so it can remain in the EU customs union, thereby being in customs union with the Republic of Ireland. This would prevent the introduction of customs controls on the border between Northern Ireland and the Republic of Ireland.

Creating a new mode of transportation between Northern Ireland and the rest of the UK, including a bridge allowing people to drive vehicles from one place to another without putting them on a ferry, would change none of that. Bridges cross customs borders all over the world. When they do, there are customs posts at one end or both. If Northern Ireland becomes a separate customs territory from the rest of the UK, there will need to be customs controls on ships and aircraft traveling between them, as well as on any bridge that might be built.

I'm not sure the DUP has actually said something like that. Channel4 may have misinterpreted the following not-so-recent statement of Paul Girvan, MP for South Antrim and DUP transport spokesperson:

As we leave the European Union, the DUP has been clear that there should be no border erected down the Irish Sea. Instead of placing barriers between parts of the United Kingdom we should be building bridges.

According to the same source, the DUP did have a feasibility study for the bridge across the North Channel in its 2015 general election manifesto. (Which Boris Johnson is now fulfilling, in that respect.)

I read that as the DUP doesn't want an Irish Sea border and they want a bridge (to Scotland), i.e. the bridge is the cherry on the cake, not a mitigating/consolation thingy.

Likewise, Arlene Foster was quoted by the BBC saying

"Whilst some foolishly attempt to use Brexit to build a border between Scotland and Northern Ireland, we are more progressive, we want to build a bridge", she said.

Now, it is possible that Boris Johnson may have obtained some concessions from the DUP in return for his support for the feasibility study for the bridge... but I haven't been able to find any confirmation or details on that. Conceivably, such concessions could be related to Brexit terms, but they could also relate to reopening Stormont, which Johnson is trying to do in order to avoid direct rule in case of a no-deal Brexit.

No it couldn't (and that's neglecting the fact that any hypothetical bridge couldn't even be built in time, in unprecedented 1000ft deep water
and somehow clearing the 1.5 million tons of WWII munitions that were dumped in the Beaufort Dyke. But those aren't even the relevant issue, they don't magically solve the issues or nullify the UK's 1998 Belfast Agreement treaty obligations to Ireland, which is what this piece of theatre is dancing around).

This is just a pre-election soundbite, not a rational engineering proposal. For a rebuttal of the technical requirements and £20++ bn estimate, see https://www.irishnews.com/news/northernirelandnews/2018/10/08/news/bridge-to-scotland-about-as-feasible-as-building-a-bridge-to-the-moon--1453026/

• You have to stop seeing Boris Johnson as a politician, and start seeing him as an unprincipled conman in a tight spot, whose career is living on borrowed time, temporarily pandering to his junior coalition partner (DUP). He only needs people to believe this until an October 2019 election. Other billion-pound promises he made recently include NHS funding and other borrowing.


• The DUP (and their Eurosceptic allies in the Tory party) want to create "facts on the ground" (to borrow the American phrase used about Iraq) to allow England to undermine and eventually violate the Belfast Agreement in the near future by reimposing border controls (both customs and immigration) with the Republic of Ireland. But a bridge cannot undo that treaty.


• The current Cons-DUP coalition has been throwing billions at the DUP since they briefly gained the balance-of-power in former PM Theresa May's disastrous 2017 election which wiped out her majority. Expect this to end the day the DUP stops holding the balance of power in Westminster, presumably Nov 2019.


• Asking the electorate to close their eyes and wish the Agreement away would be about as successful (and infinitely cheaper).