Jeremy Corbyn has unveiled a 15-page leaked Treasury document that he claimed revealed the “cold, hard facts” about the impact of Boris Johnson’s Brexit deal on Northern Ireland.
The presentation, entitled Northern Ireland Protocol: Unfettered Access to the UK Internal Market, warns that “the withdrawal agreement has the potential to separate Northern Ireland in practice from whole swathes of the UK’s internal market”.
Speaking at a press conference on Friday, Corbyn said: “This drives a coach and horses through Boris Johnson’s claim that there will be no border in the Irish Sea.”
The document suggests that for trade going from Northern Ireland to Great Britain, the government cannot rule out several different checks, including on regulations and animal health.
“At minimum, exit summary declarations will be required when goods are exported from Northern Ireland to Great Britain in order to meet EU obligations,” it says.
And for trade going the other way – from Great Britain to Northern Ireland – there could also be tariffs, the document suggests.
A section headed “economic impact on Northern Ireland” suggests high street goods are “likely to increase in price”, and many exporters could struggle with the costs of border checks, which will be “highly disruptive”.
The prime minister has repeatedly insisted the Brexit deal he struck in November will not require border checks. He even told one business in Northern Ireland that if they were asked to fill in a form, they should ring him, and “I will direct them to throw that form in the bin”.
The shadow Brexit secretary, Keir Starmer, appearing alongside Corbyn, said: “This document is significant because it is a Treasury document; this is the advice being given to the prime minister about his own deal – it’s not coming from us, it’s coming from the government.”
The document appears to have been drawn up to set out the economic and political implications of the government’s promise to maintain “unfettered access” to the British market for business in Northern Ireland.
That promise is made in the Northern Ireland protocol that replaced the backstop in Johnson’s Brexit deal.
At the event in central London, Corbyn also appeared to acknowledge that with less than a week to go until polling day, he was a divisive figure.
Asked whether he believed another leader could be more successful among working-class voters, he said: “I think Marmite’s really good for you; some people like it, some people don’t.”
Starmer, who has made few frontline media appearances during the campaign, confirmed that he would support remain in a second Brexit referendum, which Corbyn has promised to hold within six months. “I voted for remain last time and I’d do it again,” he said.