Ireland’s prime minister has said he remains concerned about the Irish border after Brexit, saying Theresa May still does not recognise the consequences of leaving the customs union and single market.

Leo Varadkar said May had given “some important reassurances” on the Good Friday agreement and the border in her speech on Friday, but they urgently needed to be backed up with detailed proposals.

“I remain concerned that some of the constraints of leaving the customs union and the single market are still not fully recognised,” the taoiseach said.



“We will now need to see more detailed and realistic proposals from the UK. Brexit is due to happen in a little over 12 months, so time is short,” he said.

Quick guide Why is the Irish border a stumbling block for Brexit? Show Hide Counties and customs Inside the EU, both Ireland and Northern Ireland are part of the single market and customs union so share the same regulations and standards, allowing a soft or invisible border between the two.

Britain’s exit from the EU – taking Northern Ireland with it – risks a return to a hard or policed border. The only way to avoid this post-Brexit is for regulations on both sides to remain more or less the same in key areas including food, animal welfare, medicines and product safety. The 'backstop' in Theresa May's Withdrawal Agreement was intended to address this - stating that if no future trade agreement could be reached between the EU and the UK, then rules and regulations would stay as they are. This has been rejected by Brexit supporters as a 'trap' to keep the UK in the EU's customs union, which would prevent the UK striking its own independent trade deals. There are an estimated 72m road vehicle crossings a year between Northern Ireland and the Republic of Ireland, and about 14% of those crossings are consignments of goods, some of which may cross the border several times before they reach a consumer. Brexit supporters say this can be managed by doing checks on goods away from the border, but critics say it will be difficult to police this without any physical infrastructure like border posts or cameras, which could raise tensions in the divided communities of Ireland.

Interactive: A typical hour in the life of the Irish border Photograph: Design Pics Inc/Design Pics RF

The deputy prime minister, Simon Coveney, welcomed the UK’s reiteration of its commitment to the Good Friday agreement, but said “these commitments now need to be translated into concrete proposals on how a hard border can be avoided”.

May has already agreed to three options for the border, two of which involve an overall UK-EU deal, or a third, bespoke solution entailing invisible electronic checks, pre-customs clearance for large traders, and waivers for small business.

Those proposals, first published in a position paper in August, were dismissed as “magical thinking” by the EU, and the Irish senator Neale Richmond said May offered no fresh detail on Friday to move any of them forward.

“It’s good that she seems to have taken the no-deal off the table, but it’s not about a soft Brexit, it’s about a workable Brexit,” he said.

The EU had raised concerns that a trade-only solution to the border issue did not take account of 142 areas, including health, security and trade, in which cross-border cooperation had flourished since the conflict ended.

Hard Brexit would hit 142 Irish cross-border agreements Read more

In her speech, May tried to push some of the responsibility for the border back on Brussels, calling on the EU to be more flexible in its approach. “We can’t do this [find a solution] on our own. It is for all of us to work together,” she said.

Coveney brushed aside any suggestion this was a plea for trilateral talks between Dublin, London and Brussels, saying all the negotiating would be done in the EU.

Northern Ireland’s leader of the Democratic Unionist party, Arlene Foster, welcomed May’s commitments to staying out of the customs union, while the Sinn Féin leader, Mary Lou McDonald, said proposals for a “fantasy technological” solution lacked credibility.