A DUP MP has challenged a logistics chief to call for the removal of the Northern Ireland Protocol as an “impediment to trade”.

Ian Paisley made the call six days into the operation of the mechanism which means the region effectively remains in the single market for goods and operates under different regulatory and customs arrangements to the rest of the UK.

The initial days of the operation have seen some lorries detained for hours over paperwork.

However, Seamus Leheny of Logistics UK queried what was available to replace the protocol, and said its removal, via article 16, could cause more chaos.

The exchange came during a session of the Northern Ireland Affairs Committee’s Brexit and the Northern Ireland Protocol inquiry.

Mr Leheny said there has been a lot of upheaval for freight operators, which he said was inevitable after the last-minute deal.

He said January is one of the quietest months of the year but volumes remain significant, with around 1,000 lorries a day entering Northern Ireland from Great Britain.

“I saw the first lorries arrive (in Belfast Port) under the terms of the protocol, on that first ship there were only 15 lorries, six of them were pulled immediately to go to the border control post because they didn’t have the correct documentation,” he told MPs.

“One large manufacturer in GB had 15 lorry loads of food to go to Northern Ireland this week, not a single one of them could move because when the lorries arrived there was no customs declaration and the operator quite rightly said, ‘there is no point in me lifting these because I’ll simply be detained or refused entry to board the ferry at Cairnryan or Liverpool.”

Mr Leheny said while most companies in Northern Ireland understand their obligations but there has been a breakdown in communication to suppliers and operators in Great Britain.

He described an operator on the opening weekend of the year who resorted to a video on You Tube for the paperwork to get lorries moving.

Giving evidence, Aodhan Connolly, director of the Northern Ireland Retail Consortium, said events so far have been characterised by traders as “opening skirmishes”.

“Retailers have been stocking up before Christmas for this first week, the flow in the first weekend was less than 20% of the usual transport flow, there are real hardships that are going to come in the middle of this month,” he told MPs.

“The big message from us is that we need the EU and UK to sit down together to talk about how the systems can be simplified and how we can get a long term workable solution because, quite frankly, this is not it.”

Victor Chestnutt, president of the Ulster Farmers’ Union, said no difference has been seen yet at the farm gate but cautioned that it was “early days”.

DUP MP Ian Paisley said a “blind man on a galloping horse” could have predicted the “unmitigated disaster”.

“I think we have to recognise that those who advocated for the protocol have some responsibility for that,” he said.

Mr Paisley went on to call for the invocation of article 16 of the protocol which allows elements of the sea border to be unilaterally disapplied.

“How bad does this have to get before you turn up at a committee like this and ask us to invoke article 16?” he challenged Mr Leheny.

Mr Leheny responded by querying what the alternative would be.

“The fear is, if you invoke this, what is the alternative?” he told MPs.

“Is it more chaos? Before you invoke article 16 you need a realistic alternative that is going to work, you just can’t simply walk away from this and think something else will be better. You need a clear plan of action on this and right now there is no clear alternative.”

Committee chair Simon Hoare also responded following a back-and-forth between the two men, commenting: “That’s a pessimistic view to take, we need to obviously keep a close eye on this and that’s why I am inviting all of our witnesses to keep us informed in real time of issues to raise with ministers.”

Meanwhile, Mr Chestnutt expressed concerns about Northern Ireland’s farmers being unable to take part in agricultural shows in Great Britain due to the new rules, and the implications of that on sales.

“It is a shelf window, that window is completely closed for the shows and the shows themselves, I fear, because you are stuck with no way home whether you intend to sell – you are over a barrel and won’t be able to operate in that marketplace,” he told MPs.

“The top breeding sales tend to be in the UK and we need to be mixing in the very top of that pool to keep Northern Ireland genetics to the fore.

“We are very concerned that we can’t get some sort of easement and I don’t think it should be impossible.”