Mary Lou McDonald (Dublin Central, Sinn Fein) | Oireachtas source

On the same issue, it is important to clarify that we cannot wish a border away. I have said to the Taoiseach that, as a matter of simple logic, we seek the backstop to avoid a hardening of the Border. Therefore, as a matter of simple logic, if there is no backstop the Border hardens. It is not just a case of saying we are not doing it because it is not just about infrastructure; it is also about standards, regulations, customs and tariffs. If the Border hardens, the international rules kick in. That is how it is.

I am no flag-bearer for the European Union but we need to deal with the facts. The danger is very real indeed and I take the view that the remedy must lie first with the British. They need to come up with the goods that honour their pledges not to undermine the Good Friday Agreement and not to see a hardening of the Border. They may not do so and we may have a crash. In those circumstances, the Taoiseach could do worse than discuss with Ms Merkel and our German colleagues the experience of German reunification.

In the event of a crash and a hardening of the Border, which we cannot wish or shout away, there will be an obligation on any Government in Dublin worthy of the name to prepare for constitutional change. If we cannot mitigate the Border or avoid the worst excesses of the damage of Brexit, then we have to move to remove the Border, democratically, peacefully, by discussion and, ideally, by consensus. This is why the Taoiseach should establish a forum on unity and speak to our German friends for guidance in this regard.

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