Northern Ireland Secretary James Brokenshire has insisted the region's voice will still be heard at a key British government Brexit committee despite his omission from its core membership.
Mr Brokenshire said he is "entirely satisfied" with the arrangement that will only see him invited to attend the European Exit and Trade Committee when permanent members think his presence is required.
The Welsh and Scottish secretaries will also attend on that basis, which has prompted claims from political rivals that the devolved regions are not central to the government's Brexit planning.
Prime Minister Theresa May will chair the Brexit committee.
Its 12 core members include Foreign Secretary Boris Johnson, Brexit Secretary David Davis and Chancellor Philip Hammond.
"I am able to attend meetings of that committee where there are Northern Ireland-related issues," said Mr Brokenshire.
"I am confident I am able to represent Northern Ireland's view, Northern Ireland's perspective, into the Brexit consideration and absolutely remain at the heart of discussions across Whitehall in ensuring the voice of Northern Ireland is heard loud and clear, and I am that champion to ensure that the issues that matter to Northern Ireland are properly reflected into the negotiation."
In an interview with BBC Radio Ulster, he added: "I am entirely satisfied that the arrangements that are in place are appropriate for me to advocate very firmly the views of Northern Ireland and to ensure we do have that loud voice in Whitehall underlining the key themes."
A government lawyer has told Britain's High Court that the parliament will "very likely" need to approve any official deal with the European Union following Brexit,
Meanwhile, a Tory peer has said there is widespread concern about the border between the Republic and Northern Ireland and a reluctance to return to a hard border.
Timothy Boswell, a member of the House of Lords EU Select Committee, has spent the past two days in Ireland, visiting both Belfast and Dublin to assess the impact of Brexit on UK-Irish relations.
Speaking on RTÉ’s Morning Ireland, he said that maintaining the border in its current status poses a problem.
He added that it was important to maintain cross-border services, such as hospital services.