Talks are to be held with Brussels over post-Brexit trade difficulties between Great Britain and Northern Ireland, Cabinet Office minister Lord Frost has said.

The Tory frontbencher told peers at his first dedicated question time in the Lords that a “specialised committee” would meet on Friday March 26, to consider “all the issues” related to implementing the part of the withdrawal deal, which seeks to avoid a hard Irish border.

Under the terms of the Northern Ireland Protocol, the region remains in the EU single market for goods and so must carry out checks at its ports despite remaining part of the UK.

This is opposed by unionists, who view it as a border in the Irish Sea.

Lord Frost sparked anger in Brussels after unilaterally extending a series of “grace periods” designed to ease trade between Northern Ireland.

He has argued this was “lawful and consistent” with the protocol.

Responding to concerns raised in the Lords over the disruption to the flow of goods between Great Britain and Northern Ireland, the Cabinet minister, who negotiated the UK’s trade deal with Brussels, said he and his staff were in “constant touch” with Commission vice president Maros Sefcovic and his team.

He said: “I am pleased to be able to say that there will be a specialised committee tomorrow within the Joint Committee framework to consider all the issues related to implementing he protocol and we continue to pursue dialogue in that framework.”

Labour former Northern Ireland secretary Lord Hain argued the minister’s “fiendishly complex barriers to trade between Great Britain and Northern Ireland were throttling local businesses and undermining political stability”.

But Lord Frost said: “The best way of dealing with the issues that are arising on trade between Great Britain and Northern Ireland is for the Northern Ireland Protocol to be implemented in a pragmatic and proportionate manner that is consistent with all its aims.”

Labour former Cabinet minister Lord Mandelson proposed a Swiss-style deal with the EU on agri-food shipments to assist trade across the Irish Sea.

The agreement avoids checks because Switzerland aligns its own regulations on animal and plant health with the bloc’s.

Lord Mandelson said: “The Government is in real danger of blundering around in Northern Ireland on these sensitive trade issues.

“The unionists feel understandably that putting a trade border down the Irish Sea is a betrayal of their community.

“To mitigate this, will the Government seek a Swiss-style veterinary agreement with the European Union, which would eliminate many of the trade barriers created.

“Is there any downside to such a veterinary agreement that is more important than smoother trade and political stability in Northern Ireland?”

Lord Frost said the UK had proposed in the trade talks last year that there could be an “equivalence arrangement” with the bloc.

He added: “Unfortunately, the EU were not open to that. We continue to be open to such an equivalent arrangement if the EU is interested in that.”

Pressed on this, he said: “The downside to a Swiss-style SPS (sanitary and phytosanitary) or veterinary agreement is that it would require our food and drink sector to accept laws that were not made in this country, but laws of the European Union.

“As far as this Government is concerned that is quite a considerable downside to such an agreement and is why we cannot accept one that is based on dynamic alignment.”