The DUP's Ian Paisley has launched a scathing attack on Prime Minister Boris Johnson, accusing him of being in danger of showing he is a "buffoon" stating Northern Ireland has "given blood to the union".
He was commenting on post-Brexit supply issues that have been reportedly affecting goods travelling from Great Britain into Northern Ireland.
It comes amid fears that the UK's relationship with the incoming Biden administration could be damaged if Boris Johnson triggers Article 16 of the Northern Ireland protocol due to the issues.
The Prime Minister has said he would not hesitate to invoke the safeguarding measure if he believed the problems with the protocol were disproportionate, however he said there had been "teething problems".
Agriculture Minister Edwin Poots said on Thursday he had been told that if the three-month grace period for supermarkets to adapt to the new rules is not extended then they won't be able to supply hospitals and schools with food in a few months time.
"That is a major crisis and I have raised this with [Cabinet Office Minister] Michael Gove, seriously are we going to have a situation where our hospitals and schools are not able to feed the children at school, that [hospitals] are not able to feed their patients?" he told the BBC.
Officials said they have not experienced any major disruption to food supplies to schools and hospitals.
Speaking to the BBC's Newsnight programme on Thursday night, Ian Paisley took aim at Boris Johnson's claim earlier this week that any issues are merely "teething problems".
"The Prime Minister is in real danger of proving to people he is actually a buffoon," he said.
"If he doesn't recognise that comments about there are really just 'teething problems' going on here and that this doesn't really matter - he really isn't in touch, he doesn't have he finger on the pulse of what's happening.
"The Prime Minister has a responsibility to get us out of this. I like the guy, I've worked with the guy, but I want Northern Ireland to enjoy every benefit it's entitled to. We've given blood for the union, in terms of our soldiers, and what do we get back? A slap in the face with a wet kipper."
It follows the North Antrim MP's appearance in the Commons earlier this week during week he rounded on Tory MPs on the benches opposite for not taking into account the impact of the Northern Ireland protocol on the region.
"What did we do? What did we do to members on those benches over there to be screwed over by this protocol?" he said.
"Ask your hearts, every single one, what did we do? Because what has happened to this protocol it is ruined trade in Northern Ireland and it is an insult to our intelligence to say it is a teething problem. Tell that to my constituents."
"This grace period needs to be extended by at least 12 months.”
The issue has led to calls from the DUP to invoke Article 16 of the Northern Ireland protocol, which allows the EU or the UK to “unilaterally take appropriate safeguard measures” if its application leads to “serious economic, societal or environmental difficulties that are liable to persist” or to diversion of trade.
The protocol has been supported by the EU and the incoming Biden administration in the US as it is seen as a way of protecting the Good Friday Agreement and preventing a hard border on the island of Ireland.
This has led to fears that, if the PM invokes Article 16, it would damage relations with Joe Biden's future government..
Conservative MP Simon Hoare said: "[Triggering the article] would do huge damage to the Good Friday Agreement... and damage the relationship between our country and the US."