Britain’s foreign secretary, Liz Truss, says she is willing to invoke Article 16 of the Northern Ireland Protocol section of the Brexit Agreement with the European Union if a way cannot be found to rewrite the agreement’s provisions covering the status of the province.

Northern Ireland is politically part of the United Kingdom, but geographically isolated. In order to avoid reintroducing a hard border between Northern Ireland and the Republic of Ireland, which could be economically destabilizing and threaten security, undermining the 1998 Good Friday Agreement, which ended decades of violent conflict in Ireland, the protocol was agreed.

Under this, Northern Ireland has continued to follow EU rules on product standards, effectively remaining in the Single Market for goods. Northern Ireland’s Unionist community, which is keen to remain part of the UK, oppose this as they see it as a sign that they are considered less British than mainland citizens.

Truss, who campaigned to remain in the EU during the 2016 referendum, took responsibility for Brexit just before Christmas, when Brexit minister David Frost resigned, following months of expressing dissatisfaction with the deal he himself had secured less than a year earlier, which he called at the time an “excellent deal… our future and our prosperity are in our hands. I am confident we will thrive and succeed”.

Truss echoed these sentiments at the time, tweeting: “Great that we have secured a trade deal with the EU … we will have a strong trading relationship with the EU and deepen our trade with partners across the world through our independent trade policy.”

But now Truss, widely tipped as a potential future Conservative Party leader, has written in The Daily Telegraph that she did not want the protocol to put at risk progress made since the Good Friday Agreement.

“As it stands, the protocol has lost the consent of the Unionist community over fears it is dividing Northern Ireland from the rest of the UK,” she wrote.

“As a sovereign nation, we cannot be in a situation where we have to notify the EU to provide vital support to businesses – such as targeted tax breaks – in one part of our country.”

This week, Truss will meet her EU counterpart Maros Sefcovic for the first time, and set out her objections and alternative suggestions.

“My absolute priority is to deal with the issues in the protocol that could threaten these hard-won gains,” she continued.

“Because, in spite of our considerable efforts to make the protocol work and our continued commitment to the principles on which it is founded, its unintended consequences are having a profound impact.”

A year ago, the EU triggered Article 16 in a row about COVID-19 vaccine supply, only to promptly reverse the decision following heavy criticism. Now, Truss says she would be willing to do the same.

“I want a negotiated solution but if we have to use legitimate provisions including Article 16, I am willing to do that. This safeguard clause was explicitly designed – and agreed to by all sides – to ease acute problems because of the sensitivity of the issues at play,” she wrote.

“The EU has already invoked this article to introduce a hard border for vaccine exports and, even in the act of withdrawing it, insisted on its right to do so again in the future.”

Speaking on Sky News, the EU ambassador to the UK, Joao Vale de Almeida, said Truss was saying nothing new.

“We’ve heard this before from the government, so we’re not surprised. We are not too impressed,” he said. “We still believe it’s not very helpful that we keep agitating the issue of Article 16.”