LEO Varadkar has told the Republic to prepare for the consequences of a no-deal Brexit, while warning that peace in the north will be jeopardised if the UK crashes out of the EU.
In the wake of Westminster's overwhelming rejection of Theresa May's withdrawal agreement on Tuesday night, the taoiseach said his government had moved from contingency planning to implementing measures for a no-deal scenario.
He warned there would be a "deeply negative impact on jobs and the economy" if the UK left without any agreement.
The Fine Gael leader's comments come after the Brexit deal agreed between Mrs May and the EU in November was resoundingly rejected by MPs in a so-called meaningful vote.
More than 100 Conservative MPs voted against their leader as the deal was defeated by 432 votes to 202.
The outcome of the vote, which had originally been scheduled to take place before Christmas, has increased the likelihood of a no-deal exit from the EU and a hard border in Ireland - the default position if no alternative is agreed before March 29.
Mr Varadkar said yesterday his government "profoundly regrets" the House of Commons' decision.
He said he would continue to work over the coming weeks with the other EU 27 countries and the British government in an effort to secure agreement, which guaranteed "that a hard border will be avoided and that citizens’ rights and freedoms will be protected".
"A no-deal scenario would have a deeply negative impact on jobs and the economy, particularly on agrifood and the traded sector – our farmers, our fishermen, our rural economy and our businessmen and women," he said.
"A no-deal scenario would not protect the peace in Northern Ireland – we will work hard to avoid it."
Mr Varadkar said the Dublin government was no longer preparing for no-deal as a contingency but had begun implementing measures to mitigate the impact of the UK crashing out of the EU.
His government will introduce special legislation in the Dáil alongside preparations at ports and airports for customs and biosecurity checks on goods.
There will also be measures to ensure medicine supplies are not interrupted and plans to support exporters and other business sectors "who may be affected severely".
He said businesses and other organisations must also begin their preparations.
The taoiseach said it should not be forgotted that "Brexit is a British policy that originated in Westminster".
"We have always said that if the United Kingdom were to evolve from its red lines on the customs union and the single market, that the European position could also evolve," he added.
"We have also always said that the risk of an unplanned, disorderly Brexit at the end of March can be avoided, including if necessary by an extension of the Article 50 deadline – this would be subject to a request from the UK being made, and agreed by all member states. "
Fianna Fáil Brexit spokeswoman Lisa Chambers said the UK needed to "outline what it wants" after rejecting the deal.
She said the outcome "magnifies the possibility of a no-deal Brexit" and that the Republic would be "worst affected" in such a scenario.
The Mayo TD said Dublin needed to intensify its preparations and share its plans with the public.
"Ministers need to trust the public and give them the information on what has been done to date and what they need to do in order to be prepared, in as much as feasibly possible, for a no-deal Brexit," she said.
"Far too many jobs and livelihoods are at stake to be ambiguous about such details."
Sinn Féin leader Mary Lou McDonald warned the absence of the withdrawal agreement backstop meant a hard border with checks.
