Irish Prime Minister Micheal Martin accused the UK of "economic damage". Martin was reacting to UK Prime Minister Boris Johnson's desire to revamp the post-Brexit Northern Ireland Protocol, which he called the worst type of unilateralism, in a BBC interview on Sunday, 

A plan tabled this week in the House of Commons would significantly alter the protocol, which presently requires customs checks on goods entering Northern Ireland from the United Kingdom. If the new bill is passed, products bound for Northern Ireland will not be subject to such checks, however, commodities bound for the Republic of Ireland via Northern Ireland will be checked and taxed at ports in the British exclave before proceeding south.

“The legislation effectively would be severely damaging to the Northern Ireland economy, particularly in the context of the dual regulatory standards approach,” Martin told the BBC, referring to the choice that Northern Irish businesses would have to make between complying with EU or UK standards.

“In effect, it represents a form of economic vandalism on Northern Ireland because if you look, any objective data is now showing that the Northern Ireland economy is doing very well,” he continued. He said that the Irish government believes that the new legislation “is very, very worrying in terms of the actual damage it could do to key sectors of Northern Ireland economy.”

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The British government claims that a dual regulatory approach would relieve burdensome EU regulations on UK-Northern Ireland trade while avoiding the return of a hard border between Northern Ireland and the Irish Republic, which would be an unwelcome reminder of the North's troubled political history.

“There are certain areas where we can improve the protocol and we should continue to do that,” Martin said, calling for “substantive negotiations between the British government and the European Union.” 

Northern Ireland's unionists – those who support the country's continued membership in the United Kingdom and see the protocol as undermining their position – have threatened not to share power with the nationalist Sinn Fein party if the protocol remains in place, and Martin has been chastised for dismissing their concerns.

"From day one Dublin has done what's in Dublin's interests and never once prioritized consensus in Northern Ireland," Democratic Unionist Party MP Sammy Wilson told the BBC. "Not one unionist MP or MLA supports the protocol but instead of Dublin trying to understand or recognize our objections, they repeatedly lecture us, talk down to us and demand we change our mind.”

Sinn Fein leader Mary Lou McDonald has stated that Britain's proposal is a "breach of international law" and would undermine the 1998 Good Friday Agreement, which ended decades of conflict in Northern Ireland.

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