The pair delivered a tough message as the EU commission president visited Dublin along with chief negotiator Michel Barnier, just a week before a crunch summit in Brussels.
Claiming there were still ‘serious’ differences with the UK over how to guarantee no hard border between the Northern Ireland and the Republic, Mr Varadkar warned there could be no agreement unless the issue was settled.
Mr Varadkar said the domestic political pressures faced by Theresa May were not ‘my concern’, and the PM must ‘honour’ her commitment to a soft border in the divorce package struck before Christmas.
‘Let me blunt, there isn’t much time left if we are to conclude an agreement and have it operational by the time the United Kingdom leaves the European Union next March,’ he told a joint press conference.
Jean-Claude Juncker (left) and Leo Varadkar (right) delivered a tough message as the EU commission president visited Dublin today
Mr Juncker (centre right) was accompanied by Michel Barnier (centre left) on the visit today
Asked about wrangling within the UK government over the customs issue, the Taoiseach said: ‘Internal British politics isn’t my concern. My job is to represent my country, Ireland, and to do that as part of the European Union and we remain at the heart of the European Union.
‘The most important aspect of the withdrawal agreement for us is the backstop, and Prime Minister May committed in March that there would be a backstop and outlined in December what that backstop would contain.’
Mr Juncker also made clear that a resolution to the border issue was crucial to the withdrawal treaty.
‘This is not a bilateral question between Ireland the United Kingdom – this is an issue between the UK and the European Union,’ he said.
‘We want to make it clear again and again that Ireland is not alone.
‘We have Ireland backed by 26 member states and the Commission – this will not change.
‘I am strongly against any temptation to isolate Ireland and not to conclude the deal on Ireland. Ireland has to be part of the deal.’
Earlier deputy Irish PM Simon Coveney indicated that a no-deal scenario was now being seriously contemplated within the EU.
‘This is a question many people are asking,’ he said.
Mr Coveney said the EU was standing firmly behind Ireland and its demand for legally binding assurances from the UK to ensure no return to a hard border on the island.
‘We have been reassured over and over again that Ireland will not be left isolated here,’ he said.
Mr Coveney added: ‘Let’s be very clear – there will be no withdrawal agreement, no transition agreement and no managed Brexit if the UK don’t follow through on their commitments.’
Mr Juncker arrived in Dublin this morning for a two-day visit as the impasse between the EU and the UK over the border continues.
Coming a week ahead of a crunch European Council meeting of leaders in Brussels, the visit is a clear demonstration of the EU’s solidarity with Ireland’s position.
This week the EU warned that more work was needed on how to deal with the 300-mile border between Northern Ireland and the Republic, the UK’s only land frontier with a European state, and protect frictionless movement after the withdrawal.
The visit by Mr Juncker (right) and Mr Barnier (left) comes just a week ahead of a crunch European Council meeting of leaders in Brussels
Mr Juncker started his visit with a meeting with Taoiseach Leo Varadkar and Mr Coveney at Government Buildings. He will later receive an honorary doctorate from the National University of Ireland and attend an official dinner hosted by Mr Varadkar in Dublin Castle.
Later on Thursday morning he will address a joint sitting of both houses of the Irish parliament, the Oireachtas.
On Friday, he will meet Irish President Michael D Higgins and visit the home of the Gaelic Athletic Association (GAA), Croke Park, and the GAA museum.
He will also watch a demonstration of Gaelic football and hurling.