Boris Johnson has been accused of misunderstanding his own Brexit deal after he again insisted his government would not implement any customs checks on goods from Northern Ireland to Great Britain.
Interviewed by the BBC on a tightly controlled visit to a hospital on Friday, the prime minister repeated a claim he made in a video that emerged overnight of a rambling speech in Northern Ireland.
Asked about customs controls on goods being moved between Northern Ireland and the rest of the UK, he said: “We are the government of the UK and we will not be instituting such checks.”
The Brexit secretary, Stephen Barclay, told the House of Lords last month that businesses would need to complete “exit summary declarations” when sending shipments from Northern Ireland to the rest of the UK.
Asked whether he was saying the government would not enforce such declarations, Johnson said: “That’s right – we’re one UK territory, we need to get this deal done, get it over the line and take the country forward.”
The shadow Brexit secretary, Keir Starmer, said: “This is a prime minister who either doesn’t know the details of the deal he has negotiated or isn’t being straight about it.
“If this deal comes into force, it’s an international treaty that will be legally binding. It’s not for Boris Johnson to waive or ignore the obligations in the deal he has negotiated. Boris Johnson’s making it up as he goes along. This is no way to seek to run the country.”
The government has repeatedly insisted that while the Brexit deal involves a new customs border down the Irish Sea, it will not require shipments of goods to be stopped and physically checked – a point made again by Johnson in Northern Ireland.
The issue goes to the heart of the collapse of the government’s relations with the Democratic Unionist party, which has described the Brexit deal as a “disgrace” and a “betrayal” because of the new customs paperwork local businesses selling goods to Great Britain will be required to complete.
On a visit to a Tayto crisp factory in Tandragee, County Armagh, on Thursday, Johnson insisted his critics had got the wrong end of the stick.
“There will not be checks, and I speak as the prime minister of the United Kingdom, and a passionate unionist. There will not be checks on goods going from Northern Ireland to Great Britain because we’re the government of the United Kingdom and we will not institute or implement or enact such checks,” he said.
“The idea that Tayto crisps from Tandragee are going to be vetted by some process is just nonsense.”
His remarks were met with incredulity as the video of his speech went viral overnight.
While there are no physical checks involved in the special Northern Ireland arrangements apart from anti-smuggling controls led by intelligence, the new paperwork that must accompany transiting goods is being seen by critics including the DUP as the erection of a trade barrier between Northern Ireland and Great Britain.
Anna Jerzewska, a customs expert, pointed out the customs controls were in the Brexit deal to facilitate the international trade agreements Johnson wants while keeping the Irish border open.
The checks and new paperwork would be needed to ensure goods from the Republic of Ireland were not smuggled into Britain through Northern Ireland.
Jonathan Portes, a professor of economics and public policy at King’s College London, said Johnson’s remarks showed he did not understand his own Brexit deal.
The DUP has said the new paperwork is an unacceptable breach of the promise there would be “unfettered” access to Great Britain for manufacturers in Northern Ireland.
The paperwork would be part of a special arrangement in which Northern Ireland would remain in the UK customs territory but follow EU customs codes on some goods transiting into Great Britain.
Johnson and his ministers have struggled to explain what this paperwork is despite being pressed several times during heated exchanges in parliament and select committees in October. Johnson has previously said businesses should not be worried because it merely involved “administrative processes”, rather than physical checks.
Local business groups have called for an urgent working group to establish what the paperwork is precisely but have said they believe a deal can be hammered out to ensure it is minimal.
Johnson told businesses on Thursday night: “Actually, Northern Ireland has got a great deal. You keep free movement, you keep access to the single market and, as it says in the deal, [you keep] unfettered access to the UK.”
The prime minister also criticised the Labour leader, Jeremy Corbyn, over the possibility of referendums on Scottish independence and EU withdrawal.
“Another turgid, torpid, toxic, appalling EU referendum, which is the last thing we need,” he said.
Johnson reiterated his dedication to the union and said he had “really good relations” with the DUP leadership.