THE potential problems around a post-Brexit border could be overcome if the north remained in the customs union and single market, one of the European Parliament's key figures has suggested.
But Guy Verhofstadt warned that responsibility for finding a workable solution lies with the British government rather than the EU.
The former Belgian prime minister, who is the European Parliament's Brexit co-ordinator, was speaking yesterday as he began a two-day fact finding visit in Belfast.
Mr Verhofstadt met academics from Queen's University and the leaders of Stormont's five main parties, before travelling to a 220-acre farm of the Hughes family straddling the Monaghan-Armagh border.
He is expected to meet Taoiseach Leo Varadkar in Dublin today ahead of addressing a special joint sitting of a number of Oireachtas committees.
Sinn Féin said last night its MPs will attend the address in the Dáil chamber.
Speaking to the Press Association in Belfast, Mr Verhofstadt said a "unique solution" was needed to avoid a hard border.
"A unique solution in that there is no resurrection of a hard border in Northern Ireland because that is not in the interests of business in Northern Ireland and Ireland, neither in the interests of the citizens."
He added that the potential problems with the border were a "consequence of the decision of the UK to leave the European Union" and the "solution has to be proposed by the UK side".
Mr Verhofstadt, who is the link man between the EU negotiating team and the European Parliament, was sceptical about proposals in a British government's position paper which suggested there would be no need for physical customs checks on the frontier even if the UK was outside the customs union.
"For the moment we don't see a workable solution being put forward by the UK government."
However, in an interview with RTE radio, he said "you could imagine one proposal on the table that Northern Ireland continued to be part of the customs union and even of the single market".
"The point is it is the UK government that has to come forward with such unique solutions," he said.
The MEP's visit to Ireland comes ahead of a crucial summit in Brussels next month when leaders of the 27 EU states will decide whether sufficient progress has been made in the first phase of Brexit negotiations to progress talks to focus on future trading relations.
The EU has insisted progress has to be made in three key areas: citizens' rights, the size of the UK's exit bill and the shape of the Irish border post-Brexit.
Asked about speculation that Prime Minister Theresa May will outline a sum the UK is prepared to pay in a keynote speech on Friday, Mr Verhofstadt said: "Let's have the speech of Mrs May and then we can make an analysis."
After meeting with the European Parliament representative, DUP leader Arlene Foster said the retention of the common travel area between Ireland and Britain was vital.
The former first minister also reiterated her desire for the border to be "open and seamless".
However, she insisted that any solution must be "UK-wide".
"We will not countenance any customs deal that cuts Northern Ireland adrift from our primary marketplace – that was the message we delivered to Mr Verhofstadt," she said.
"Whether it be in terms of transition or future trade relations with those in the single market, Northern Ireland must be treated in the same fashion as the rest of the UK."
Sinn Féin northern leader Michelle O'Neill claimed Mr Verhofstadt had been dismissive of the British position papers to date.
"I believe he's someone who has been very aware of the implications of Brexit on the island of Ireland and someone who has been very strong in setting out his position on issues which need to be resolved before moving on to the next stage of negotiations," she said.
SDLP leader Colum Eastwood said there was an "economic and political tsunami" heading for Northern Ireland and Mr Verhofstadt shared his party's position.
"He understands that we need to accommodate the unique circumstances in Northern Ireland, he understands that people in Northern Ireland voted to remain and that has to be respected."
UUP leader Robin Swann said the lack of a Stormont executive was harming the region at a crucial time.
"It was shame and disgrace today that we were meeting as individual parties and there wasn't an executive representing Northern Ireland in what is a crucial moment and crucial activity in how Northern Ireland progresses at this moment in time," he said.
Former Alliance party justice minister David Ford said their discussions had included how the UK's withdrawal from the EU could impact on cross-border security issues.
