BORIS Johnson’s move to tear up the Northern Ireland protocol is a “slam dunk breach of an international agreement”, the Sinn Fein Stormont leader has said.

Michelle O’Neill said the “reckless” action would undermine the Good Friday Agreement and have “huge economic consequences”.

Warnings have also been issued that it will have a “destabilising” effect on politics in Northern Ireland.

Ireland’s Foreign Affairs Minister Simon Coveney described it as a “new low in British-Irish relations” in the past 25 years.

The UK Government has published a bill to overhaul the Protocol, allowing it to renege on the commitments it made to the EU in the post-Brexit deal signed in 2020.

But the EU is expected to take legal action this week over the plans, which aim to scrap current checks on some goods travelling from Great Britain to Northern Ireland.

READ MORE: EU could take legal action against NI Protocol Bill as early as this week, reports say

O’Neill described the UK Government’s action as “disgraceful and utterly reckless”.

“It’s a straight up, slam dunk breach of an international agreement,” she told RTE Morning Ireland.

“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.”

The National: Irish Minister for Foreign Affairs Simon CoveneyIrish Minister for Foreign Affairs Simon Coveney

Coveney told BBC Good Morning Ulster “it is going to destabilise what is already a difficult situation”.

He said: “What the British Government is proposing to do is dismantle the protocol, which is international law, which was carefully put together over a number of years through painstaking negotiation involving this British Prime Minister to solve or to manage the disruption of Brexit on the island of Ireland as best we could.

“The British Government is now looking to undermine all of that work for whatever political reason.”

He added: “This, I think, is really a new low in British-Irish relations, certainly, I think in the last 25 years or so.”

Irish premier Michael Martin also warned the legislation to override parts of the Northern Ireland Protocol is “anti-business and anti-industry”.

He said that the UK Government’s plans make it difficult to avoid acrimony or real difficulty.

Speaking in Dublin, he said the proposed legislation would have a destabilising effect on politics in Northern Ireland.

“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,” he added.

“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.”

However, Foreign Secretary Liz Truss claimed there was “absolutely no reason” for the European Union to retaliate against the UK.

READ MORE: Boris Johnson claims Northern Ireland Protocol Bill changes 'not a big deal'

She told Times Radio: “Our solution doesn’t make the EU any worse off. We continue to protect the single market, we’re supplying the EU with data, we’ve got strong enforcement to make sure companies aren’t violating the rules.

“So there is absolutely no reason why the EU should react in a negative way to what we’re doing.”

Truss also told the BBC Good Morning Ulster programme the UK Government felt it “absolutely had to take action” because of the current situation in Northern Ireland.

The National: Foreign Secretary Liz Truss Foreign Secretary Liz Truss

She said: “The fact is that the Belfast/Good Friday Agreement is being undermined. We haven’t seen an Executive formed since February, we have seen east-west trade diminished, trade diverted to north-south. We’ve also seen the people of Northern Ireland not able to benefit from tax breaks.

“These are all issues that we need to sort out. Our preference is to sort them out with the EU, but as yet the EU are not agreeing to change the text of the protocol.”

READ MORE: Boris Johnson risks backbench rebellion over plan to rip up Northern Ireland Protocol

DUP leader Sir Jeffrey Donaldson described the UK Government’s action as “balanced and fair”.

“The Government is entitled under the protocol to take unilateral action where there has been societal, economic or political harm caused by the protocol,” he told the BBC’s Good Morning Ulster programme.

“Therefore I think the Government is entirely within its rights and entitled to do this.

“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."