UK Prime Minister Theresa May said Britain's divorce agreement with the European Union It has resolved 95 percent, but admitted that the problem of the Irish border was still a "considerable" point.
Addressing the British parliament on Monday, May said the United Kingdom could request a short extension of a planned transition period to facilitate its exit from the European Union, or Brexit, to be held on March 29, 2019.
"There are some limited circumstances in which it could be argued that an extension of the implementation period might be preferable if we were sure it was only for a short time," May told lawmakers in London.
The prime minister was updating the parliament at a summit of EU leaders in Brussels last week, where she tried to advance an agreement on the terms of the UK withdrawal from the bloc.
He reported on progress on some issues, including in the areas of security, defense and Gibraltar, and noted that "95 percent of the retirement agreement and its protocols are already resolved."
Gibraltar, a British overseas territory located at the tip of the Iberian Peninsula and regularly claimed by Spain, will leave the EU along with the United Kingdom.
The five percent hardest
But May also admitted that the question of how to avoid a so-called "hard border" between Ireland and Northern Ireland remains a major and unresolved challenge.
"There is a real point of friction to the left, but considerable," he said, referring to the Irish question.
When Britain leaves the bloc, it will be necessary to draw some kind of border between Northern Ireland, which is part of the United Kingdom, and Ireland, which is a member of the EU, to allow customs controls of goods, products and livestock.
Both the United Kingdom and the EU are willing to avoid a hard border, which would be monitored and involve stops and controls at crossing points.
The two sides accept that a "back-up" solution is desirable in the event that the UK leaves the EU without a full withdrawal agreement, even if they do not agree with what the endorsement would imply.
The EU has proposed a support that would imply that Northern Ireland will remain in the EU customs union and much of its single market.
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This solution would redraw the border between the United Kingdom and the EU in the Irish Sea, a result that London wants to avoid.
May has proposed that the entire UK remain in the EU customs union. Brussels is considering this now, but has not been prepared to accept the proposal so far.
The EU has also volunteered to extend the post-Brexit status-quo transition period by one year. Currently, the transition period will close at the end of 2020.
May said last week he was open to an extension, a move that drew strong criticism from members of his conservative party.
On Monday, she reiterated the position, stating that the UK may need a short extension "as an alternative to support."
"I have not committed to extend the implementation period," he said. "I see any extension, or be in any form of backup, as undesirable."
Reporting from London, Nadim Baba of Al Jazeera said his position as party leader appeared to be in jeopardy, amid rumors of leadership challenges.
"It seems that it is becoming more precarious," he said. "We are listening to that centrist. Conservative Parliamentarians now join dozens of people who have sent letters to the party presidency, asking them to basically launch a leadership contest.
Baba added that May is expected to hold a cabinet session on Tuesday, before meeting with the backbenchers a day later.
"We've had rumors of challenges before and they have not gone anywhere, but the clock is really running," he said.
"A lot of people say that this is just to add pressure on her so she does not give in to Brussels in terms of that transition period."
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Al Jazeera and news agencies.