The Irish Government needs to “get real” about the problems being caused by the Northern Ireland Protocol, DUP leader Sir Jeffrey Donaldson has said.

Irish Foreign Affairs Minister Simon Coveney has been fiercely critical of the UK Government’s plans to override parts of the international deal which was struck over Northern Ireland’s post-Brexit trading arrangements.

Mr Coveney warned the move could “destabilise” the situation in Northern Ireland and was undermining the work that led to the Brexit agreement with the EU.

BrexitIrish Minister for Foreign Affairs Simon Coveney said UK Government action on the NI Protocol could destabilise the situation in Northern Ireland (Niall Carson/PA)

But Sir Jeffrey responded: “Simon Coveney fails to recognise the extent of the problems that the protocol is causing for Northern Ireland.”

He told the BBC: “It is not just about trade, it is not just about the difficulties it is creating for business, it is not just about the impact this is having on the cost of living for every consumer in Northern Ireland, it is also about our political institutions.

“It is about stability. Not a single unionist MLA elected to the Assembly last month supports the protocol and without that cross-community consensus the political institutions cannot operate.

“I think the Irish Government need to get real, they need to understand the extent of the problem here and stop deluding themselves that it is some kind of minor issue.

“As for negotiations, Simon Coveney talks about sitting around the table – the problem is we’ve had two years of negotiation and no progress.”

Irish premier Micheal Martin said the legislation is “anti-business and anti-industry”.

“The fundamental issue is one of trust because the EU did enter an international agreement with the UK Government, which is now, essentially, being reneged upon,” Mr Martin added.

BrexitDUP leader Sir Jeffrey Donaldson said UK action over the NI Protocol was fair and balanced (Liam McBurney/PA)

“A lot of European Union leaders are going to say: ‘How are we going to trust you again if we do a further deal? How do we know you will adhere to that deal?’

“That is a fundamental issue that now has to be overcome. I think the EU will uphold its side and also seek to press the full adherence to the agreement.

“Nobody wants to be in a situation where we end up in acrimony or real difficulty, but I am afraid the British Government’s decision to unilaterally press ahead with this legislation, which is ill-thought-out anyway, in terms of the detail of it, I think makes for very difficult times ahead.”

He added: “I don’t think it’s well-thought-out-or well-thought-through and certainly doesn’t match the realities on the ground in terms of experiences of those involved in various industries.

“For example, those involved in manufacturing are doing particularly well under the protocol and they’re now very concerned, not just by the uncertainty that has been created, but also the fact that this represents an undermining of conditions.”

The protocol arrangements require regulatory checks and customs declarations on goods moving between Great Britain and Northern Ireland.

Unionists in Northern Ireland are vociferously opposed to the international treaty, claiming it has undermined the region’s place within the United Kingdom.

The DUP has blocked the formation of a new power-sharing government at Stormont following last month’s Assembly election in protest.

Sir Jeffrey said the UK Government was entitled to take unilateral action over the arrangements.

He said: “What we need is a permanent solution here, and that is why I think it is important that the Government is bringing forward this legislation, and I think what the Government has proposed is balanced, it is fair.

“It enables us to see Northern Ireland’s place within the UK’s internal market restored in line with the commitment the Government gave in New Decade, New Approach over two-and-a-half years ago now.”

BrexitSinn Fein vice president Michelle O’Neill said the UK Government had undermined the Good Friday Agreement (Liam McBurney/PA)

But Sinn Fein’s Stormont leader Michelle O’Neill said the UK Government’s actions were a “straight up, slam dunk breach of an international agreement”.

She told RTE: “It undermines the Good Friday Agreement, and their actions will have huge economic consequences because the reality is, and everybody bar the DUP and bar Boris Johnson knows, that the protocol is working.

“It’s given us an economic advantage. Our economy is outperforming that of Britain and that’s I think what they want to hide in this.

“Boris Johnson’s action yesterday is just completely reckless, and serves to create more instability and serves to create more uncertainty for businesses for planning for the future.”

Ms O’Neill added: “From the very outset of the Brexit debate, we said that the Good Friday Agreement and Brexit were incompatible.

“We didn’t consent to Brexit, but it’s still being foisted upon us.

“We sought to find some mitigation in the form of the protocol.

“It protects the all-island economy which is flourishing as a direct result of the protocol.”