The EU could have endangered vaccine supplies to Northern Ireland by enforcing Irish Sea trade disruption, the health minister said.

The Oxford AstraZeneca jab is manufactured in the UK but the Pfizer BioNTech’s vaccine comes from a plant in Belgium, and has in the past been routed to Belfast via Dublin.

The European Commission was forced into an embarrassing U-turn on Friday when it backtracked on an attempt to restrict the free flow of vaccine across the Irish border.

Robin Swann said: “This had potentially very real implications for ourselves because we had vaccine actually in transit, and had that article been enforced we may have seen difficulties in the supply and the arrival of vaccines here in Northern Ireland.”

More than 246,000 doses have been administered.

Mr Swann said: “Vaccine is not something that should become political.”

Arlene Foster has accused Boris Johnson of a dereliction of duty and claimed he is not doing enough to address unionist “anguish” over Irish Sea trade disruption.

Northern Ireland’s First Minister demanded action from the Prime Minister following the EU’s “horrific” botched move to invoke a mechanism to suspend elements of the new post-Brexit arrangements.

Mrs Foster told BBC Radio Ulster: “I have to say directly to the Prime Minister and to the UK Government that it is a dereliction of duty for a prime minister of the United Kingdom to stand by and allow United Kingdom citizens to suffer, and that is what he is allowing to do at present, so therefore action is absolutely needed.”

A further 11 people have died after testing positive for Covid-19 in Northern Ireland.

The Department of Health also confirmed another 314 positive cases of the virus on Monday.

There are 735 patients with Covid-19 in hospital, including 64 in ICU.

Senior European politicians have conceded it was a mistake to try to unilaterally suspend part of Brexit’s Northern Ireland Protocol to prevent the region being used as backdoor to move inoculations from the bloc into the UK.

The protocol, which governs the movement of goods in and out of Northern Ireland post-Brexit, was created to ensure continued free flow of trade across the Irish border.

It does so by moving regulatory and customs processes to the Irish Sea, with checks instead focused primarily on produce moving from Great Britain into Northern Ireland.

Some aspects of trade have experienced disruption since the protocol came into effect on December 31 and unionists have been calling for the UK Government to itself suspend elements of the protocol using part of the agreement called Article 16 until the issues have been resolved.

The First Minister told the Stormont Assembly: “The protocol was imposed upon the people of Northern Ireland. I have always opposed it.

“Despite significant protestation and logical argument against its provision, it is still here.”

She said the EU still holds the power to invoke Article 16 in reserve.

“It has caused significant dismay and distress. It is wrong and unnecessary and we all know that is the case.”

She accused the bloc of threatening to trigger Article 16 “without consultation, without thought or consideration of the welfare of the people of Northern Ireland”.

The DUP leader added: “Too many people have been fooled by what it seemed on paper, but reality has bit and unionists across the length and breadth of Northern Ireland are in anguish.

“It should matter that everyone in Northern Ireland is being denied supply of trade and if they really care about all of the people of Northern Ireland they will act.”

Senior Sinn Fein representative John O’Dowd urged unionists to stop “sabre-rattling” and called for calm heads and measured words rather than violence.

He said: “Many in this society have faced the inside of courtrooms, police stations and jails because of loud voices from people who march them up to the top of the hill and then leave them there.”

The Upper Bann Assembly Member said the Commission was wrong in its actions last week and acknowledged fears over the protocol.

He told the Northern Ireland Assembly: “There are genuine concerns within the unionist community.

“We are prepared to listen to them, we are prepared to work with them.”

Ulster Unionist leader Steve Aiken said he is not trying to inflame tensions.

He reiterated his demands for invocation of Article 16 by the UK to ease east/west trade.

“Our economy, our society and our culture, and virtually every aspect of Northern Ireland’s life, is being impacted.

“We, as a unionist party, have said for a considerable time that Article 16 should be there and should be used.”

A UK Government spokesman said: “We will continue to work quickly to ensure the operation of the Northern Ireland Protocol is as smooth as possible and to address any sources of concern.

“The Chancellor of the Duchy of Lancaster (Michael Gove) and EU Commission vice president, Maros Sefcovic, have agreed to redouble their efforts to make sure that these arrangements work for the people of Northern Ireland.”