A Brexit deal over the Irish border could be reached by the end of November, Ireland's deputy premier has said.

At a meeting of the British-Irish Intergovernmental Conference in Dublin, Simon Coveney said “a lot of progress” had been made by negotiating teams in recent weeks.

His comments were echoed by UK Minister for the Cabinet Office David Lidington, who said negotiators were “very close” - and said he hopes and expects that a deal would be secured in the next few weeks.

However, critics accused Brexit minister Dominic Raab, who was in Northern Ireland at the same time, of carrying out a "fly-by-night" visit as part of a "box-ticking exercise", instead of offering a real solution.

When questioned by the media, Mr Raab was tight-lipped about how negotiations were going during his visit to Belfast.

But in Dublin, Mr Coveney said the EU chief negotiator Michel Barnier has shown “flexibility and imagination" to overcome some of the political challenges that were "clearly there”.

“I think a deal can be done, but I think it’s important that the commitments that have been made are followed through on in full,” he said.

“If that happens, I think it’s possible to ensure that we get a withdrawal agreement that can be sold on both sides of the Irish Sea.

“I think it is possible to get a deal in November."

Brexit Secretary Dominic Raab arrives at Stormont House in Belfast during his visit to Northern Ireland Credit: Brian Lawless/PA

Mr Lidington said he believed they were “very close to resolving” the outstanding issues, and he reiterated the UK Government’s commitment “to getting over those final difficulties” in the Brexit negotiations as soon as possible.

“I cannot emphasise strongly enough that the Prime Minister feels absolutely committed to her pledge not to have under any circumstances a hard border on the island of Ireland,” Mr Lidington said.

In Belfast, Mr Raab pledged that his government would not sign up to any deal which might threaten the constitutional integrity of the UK.

Mr Raab made the comment following a one-day visit to Northern Ireland.

He visited two sea ports before meeting a number of local political parties.

Mr Raab heard opposing views from the two biggest parties, the Democratic Unionists and Sinn Fein.

The DUP urged that there should be no additional barriers between Northern Ireland and the rest of the UK after Brexit.

Sinn Fein told him that the UK government must agree to a backstop plan which could see Northern Ireland effectively remaining in the customs union and single market.

However, Mr Raab insisted he is confident the Government can get a “good deal”.

“We have made it very clear we would never sign up to anything that would threaten the economic, the constitutional, let alone the territorial integrity of the United Kingdom,” he told the BBC.

Sinn Fein leader Mary Lou McDonald (right) and deputy leader Michelle O’Neill speaking to the media in the Great Hall at Stormont, Belfast, following a meeting with Brexit Secretary Dominic Raab Credit: Brian Lawless/PA

“We are engaged in negotiations, I need to protect the integrity of those negotiations, but we are confident we can get a good deal, good for all corners of the United Kingdom and good for every community here in Northern Ireland.”

DUP leader Arlene Foster said her party wants a deal that is good for Northern Ireland, adding: “it can only be good for Northern Ireland if we remain a full part of the United Kingdom.”

However, Sinn Fein President Mary-Lou McDonald accused the UK government of “acting in bad faith”.

“We have reminded him that he and his government last December signed up to that, understood that the north of Ireland is a particular scenario with a need for a bespoke and particular solution,” she said.

DUP leader Arlene Foster (right) and deputy leader Nigel Dodds speaking to the media in the Great Hall at Stormont, Belfast Credit: Brian Lawless/PA

She added: "We have told him that he and his government are acting in bad faith, that they have stepped back from the commitments that they made to protect the Good Friday Agreement in all of its parts, to ensure no hardening of the border on our island and to ensure no loss of rights for our citizens.”

Ulster Unionist leader Robin Swann expressed disappointment that Mr Raab had not stayed longer, pointing out such visits were particularly important in the absence of the Northern Ireland Executive to speak for the region.

SDLP leader Colum Eastwood and Alliance Party leader Naomi Long also pressed Mr Raab for a backstop plan.

Mr Raab started his day in Northern Ireland with a visit to Warrenpoint Port in Co Down.

He was criticised there for not meeting with public representatives and local people.

Sinn Fein MP Chris Hazzard said: “Dominic Raab is like a thief in the night coming in and out, not providing opportunity, not just me personally but the people I represent.”