The Taoiseach will meet with the President of the EU Council in Dublin today as Brexit talks intensify.
Both Donald Tusk and Leo Varadkar have floated the idea of the North staying in the customs union and the single market.
The meeting comes as British MPs warn that a return of border checks between the North and Ireland appears inevitable after Britain leaves the EU.
The Commons Exiting the EU Committee said it appeared impossible to reconcile the British Government’s decision to pull out of the single market and the customs union with its declared intention to maintain a “frictionless” border.
It said the UK Government’s proposals for dealing with the issue, including using technology to create a “light touch” border, were “untested and to some extent speculative”.
“We do not currently see how it will be possible to reconcile there being no border with the Government’s policy of leaving the single market and the customs union, which will inevitably make the border between Northern Ireland and the Republic of Ireland the EU’s customs border with the UK,” the committee said.
But the report split the committee with four of the eight Conservatives present as well as the lone Democratic Unionist voting to reject it.
The findings echo the concerns of the government which has demanded a written guarantee from the UK that there will be no return to the “hard border” of the past as a result of Brexit.
Taoiseach Leo Varadkar has warned that without such an assurance, EU leaders will not give the green light for the second phase of the Brexit negotiations, including talks on a free trade deal, to begin at their summit on December 14 and 15.
In its report, the committee urged the British Government to begin work on ensuring the flow of goods in and out of the UK continued as freely as possible, regardless of whether there was a deal, including installing electronic customs checks and the construction of a lorry park at the Port of Dover.
But it added: “Such measures would not deal with all the risks of serious delays in Dover and would have to be reciprocated across the Channel in order to be effective.”
The report also called on ministers to publish a white paper explaining how its proposed two-year transition period after the UK leaves the EU in March 2019 would work in practice.
It said any agreement between the UK and the EU on future citizens’ right should be “ring-fenced” to ensure the status of EU nationals living in the UK and British nationals in the EU was guaranteed regardless of whether there was a wider deal.
One the four Tory Brexiteers who voted against the report, Craig Mackinlay rejected the suggestion that leaving the single market and the customs union would mean bringing back a “physical border infrastructure” between the North and Ireland.
“Of course, there has long been a VAT and currency border. Goods and services entailing cross-border transactions have paperwork and electronic filing to efficiently and effectively handle the different tax regimes,” he said.
“If we end up with the World Trade Organisation model, for instance, I see no reason why it is not possible to add a customs tariff, if necessary under a no deal scenario.”