Leo Varadkar is in London today for his first meeting as Taoiseach with the British Prime Minister.
It comes on the day the UK begins formal negotiations to leave the EU.
The UK’s Brexit Secretary David Davis and the EU’s chief negotiator Michel Barnier will hold talks in Brussels – with the Northern Ireland border set to feature on the agenda.
Britain’s Chancellor of the Exchequer yesterday said the UK will definitely be leaving both the EU single market and the customs union.
Danny McCoy, the CEO of business lobby group IBEC, says that would pose a huge challenge for Ireland.