Withdrawal Agreement is not up for re-negotiation per Irish Minister for Foreign Affairs
July 19,2019
RTÉ News
...When asked for his reaction to private EU concerns about Ireland's no-deal planning, Mr Coveney said that the Government would not compromise Ireland's place in the Single Market to avoid a hard border, nor would it risk security on the island.
"Ireland is not going to allow a situation where the Republic of Ireland effectively gets dragged out of the EU Single Market. This is a Single Market we're part of, we helped to create and we're going to stay part of and in order to do that we need to protect the integrity of the EU Single Market in Ireland, otherwise we would potentially face checks on goods leaving the Republic of Ireland going to other parts of the Single Market.
"So, we're going to do that in a way that doesn't pose a security risk or undermine a peace process on the island of Ireland and the European Commission is working with us on that."
https://www.rte.ie/news/europe/2019/0719/1064029-merkel-irish-border-comment/