Hoping that a final Brexit agreement will be reached by the start of the EU summit later today, UK Prime Minister Boris Johnson is heading to Brussels.
The two sides have reportedly been closer than ever in an agreement to replace the so-called backstop, which aims to avoid a hard border in Ireland.
European leaders have said they will not negotiate the deal themselves at their summit, so the British side is either seeking a draft law on the new Brexit terms in advance, or gaining the political approval of the leaders and then there will be a new session to approve the legal text.
According to the British media, there has been sufficient convergence between London and Brussels on the issue of Northern Ireland's customs relationship with both the EU and the rest of the United Kingdom.
In particular, it is believed that Northern Ireland will be legally outside the European Customs Union and will belong to the United Kingdom through customs, but will continue to impose EU tariffs. At the same time, a compensation system will apply to companies moving goods between the UK and Ireland and will be affected by the different duties.
An agreement has also been reached on the mechanism for regularly renewing the Northern Ireland residence permit in the European single market. It is specifically believed that the Stormont National Assembly will be given the opportunity to define this mechanism.
On these points, however, there must be a consensus from the Democratic Unionist Party of Northern Ireland (DUP), so that there is hope that the agreement will be approved by the House of Commons.
On the contrary, disagreement between the British government and the EU is said to continue in the VAT regime in Northern Ireland, which concerns the future of bilateral trade.
Informing the cabinet on Wednesday afternoon, Prime Minister Johnson said the deal was close, but added that "the top is still covered in fog."
The British Prime Minister also had successive meetings with both the DUP and the Conservative MPs who belong to the highly Eurosceptic ERG group.
If Boris Johnson does not reach an agreement with the Europeans within the next two days, the law obliges him to request a three-month extension of Brexit on Saturday until the end of January.
Despite repeated assurances from Downing Street that Brexit would take place on October 31, Brexit Minister Steven Barkley told a parliamentary committee on Wednesday that the prime minister would send a letter to the president's request for a postponement if necessary.