During a visit to Northern Ireland on Tuesday, the prime minister is likely to repeat the government's insistence on avoiding a hard border with the Irish Republic after the UK leaves the EU.
All sides are keen to avoid a return to the checkpoints and customs controls of days gone by - none more so than those in the Republic of Ireland. The nation's economy is umbilically tied to the United Kingdom; Brexit could have huge implications on that.
A no-deal Brexit would create unwanted obstacles for the Irish economy.
The country's economic growth could be sliced in half after to Brexit, analysis says. The majority of Ireland's exports are either sold to or pass through Britain. As Whitehall tears itself apart over Brexit, Ireland has been busy expanding its sea ports, shoring up extra capacity to cut out the middleman - that's the UK.
However, the ever-problematic land border brings hurdles that aren't so easy to leap. Horse racing brings in €1.8 billion (£1.5 billion) to the country's coffers every year - making it worth more, and supporting twice as many jobs, as Britain's fishing industry. But the business relies on freedom of movement for both people and their animals.
It's estimated that 25,000 individual horse journeys are made every year between Ireland, the United Kingdom and France. The chief executive of Horse Racing Ireland Racecourses, John Osborne, has told ITV News that a no-deal Brexit would be "disruptive at the very minimum," adding that it will have "serious implications," for the industry.
Ryanair, one of Ireland's biggest businesses, on Mondayannounced its first loss in five years. The budget airline said it has been forced to make preparations for Brexit - but it doesn't know what kind of Brexit that will be.
Its chief financial officer, Neil Sorahan, said that there are risks around the currency, adding that the airline "would like certainty around what's going to happen over Brexit," and if - or when - it will need to put its emergency plans in place.
Brexit is already changing Ireland in a way people did not ask for - for better and for worse. But there's an understanding that however a no-deal might hit the EU, the impact will be felt in Irish towns and cities first.
With just 53 days until Brexit must be signed, sealed and delivered, the clock is ticking - and some are anticipating negotiations will come to a close with a photo finish.