Safety fears suspend work for EU staff at Northern Irish ports

"We have asked them [EU customs officials] not to attend their duties today, and we will continue to monitor the situation and adapt accordingly," commission spokesman Eric Mamer told reporters on Tuesday.

"For us, the utmost priority is the safety of people," he added.

On Wednesday, the issue will be discussed at a video conference between commission vice president Maroš Šefcovic, British cabinet minister Michael Gove, Northern Ireland's first minister Arlene Foster, and deputy first minister Michelle O'Neill.

The precautionary move to stay home comes after unionist paramilitary groups threatened local port staff and identified them as "targets", including in graffiti.

Northern Ireland authorities suspended food checks at Larne and Belfast ports, which take place under the post-Brexit arrangements.

Irish prime minister Micheal Martin called it "an ugly and sinister development."

There has been anger among unionists against the Northern Ireland protocol, introduced at the start of the year, which is seen as potentially dividing the UK.

The protocol, part of the EU-UK withdrawal agreement, has placed checks at Northern Ireland ports themselves, to avoid checkpoints at the politically-sensitive land border between Northern Ireland and the Republic of Ireland. The conflict between protestant unionists and catholic republicans saw decades of terrorism and civil unrest.

"We condemn very strongly any threat of violence against port officials or anybody else in Northern Ireland who are simply exercising their duties and implementing the withdrawal agreement," Mamer said.

"Whatever the reason, the threat of violence is unacceptable, full stop," Mamer added, saying that - to the commission's knowledge - the recent tension flared up before the EU executive mulled triggering a suspension of the protocol last Friday, in a row over vaccine exports.

What is Article 16?

Under the Brexit withdrawal agreement the Northern Ireland protocol deals with keeping the physical land border between Northern Ireland and the Republic of Ireland open, to avoid a flare-up of sectarian tensions there.

Under the protocol, goods can be traded with some checks now introduced at the province's maritime ports - as Northern Ireland effectively remains part of the EU's single market for goods and custom rules.

Some physical checks take place in four, EU-approved, Northern Ireland ports for agri-food goods, plants and animals, to secure the EU's sanitary standards.

The protocol was a hard-won and long-fought mechanism during the London-Brussels Brexit negotiations.

Article 16 of the protocol allows the UK or the EU to temporarily suspend its operations if they lead to "serious economic, societal or environmental difficulties", although it does not specify what "serious" entails.

As a response, the other side can take "rebalancing measures".

Article 16 was meant to be used as a last resort.

However, the EU Commission last Friday (29 January) initially triggered Article 16, as part of its efforts to force pharmaceutical companies to ask for export authorisation to moves vaccines out of the EU bloc.

The worry was that Northern Ireland could present a back door for vaccines to move into the UK.

But faced with the outrage from London, Dublin and Belfast, the commission quickly reversed course, and in its final decision on the trade authorisation, published Friday night, it did not include triggering Article 16.