The prime minister gave the clearest acknowledgement yet that the costly red tape is the consequence of the Brexit deal he signed in 2019 and hailed as “fantastic’ at the time.
On his visit to Belfast, Mr Johnson was told he “must be furious with whoever signed up to a deal this bad”.
It was pointed out that the checks required from creating a trade border in the Irish Sea were all set out clearly in a government impact assessment, in 2019.
A leaked Treasury paper the same year, warned the Protocol would be “highly disruptive” to the Northern Ireland economy” and would push up the price of high street goods.
Mr Johnson and other ministers have repeatedly accused Brussels of implementing the trade checks in a way not justified by the terms of the withdrawal agreement.
But the prime minister switched tack, telling Channel 4 News: “I hoped and believed that our friends would not necessarily want to apply the Protocol in quite the way that they have.”
Chris Bryant, a Labour MP, protested: “He told a lie to the British public. Again he tells allies the UK word cannot be trusted.”
In a separate interview, Mr Johnson was asked if the crisis and the risk of a trade war with the EU is “a direct consequence of the deal you signed,” replying: “Yes absolutely.”
Talks to try to find a solution are on ice, with London and Brussels accusing the other of refusing to compromise to reach a deal to prevent the worst of the extra bureaucracy.
Instead, Mr Johnson is pressing ahead with unilateral action to override the Protocol through new legislation – almost certainly in breach of international law.
The 2019 impact assessment directly contradicts UK denials that the checks were not intended, stating:
* On customs, that checks will be implemented “on trade moving East-West between Great Britain and Northern Ireland”.
* On food checks, that they would include “identity, documentary and physical checks by UK authorities as required by the relevant EU rules”.
* That agri-foods must “enter Northern Ireland from Great Britain via a Border Inspection Post or designated point of entry as required under EU law”.