Boris Johnson has been warned he must break his promise not to impose trade checks in the Irish Sea after Brexit or face legal action from the EU.
The prime minister was warned by a senior aide to Brussels chief Brexit negotiator Michel Barnier that the EU “will not tolerate any backsliding or half measures”.
Johnson has repeatedly claimed there will be no checks on trade between Great Britain and Northern Ireland as a result of his Brexit deal, insisting on Wednesday that the province would “emphatically” still have “unfettered” access to the rest of the UK after Brexit.
But Barnier’s adviser, Stefaan De Rynck, stressed that the Brexit deal negotiated by the PM includes a commitment from the UK to impose “checks” on goods, including food and agri-food, heading to Northern Ireland to ensure they comply with EU customs and single market rules.
He made clear that Johnson must implement what he agreed, including checks, by the end of the year or face enforcement action under the terms of the deal.
He told an event at University College London: “We will have to be extremely disciplined to get it up and running in 11 months, to have the UK authorities apply the checks that the UK has agreed to apply. The union’s customs code (and) the union’s single market standards continue to apply in Northern Ireland as of 2021.”
He went on: “That creates quite a bit of preparatory measures that are needed and ... certainly we will not tolerate any backsliding or half measures.
“The protocol is clear on what needs to be done by both sides and we will want to stick to that.”
Johnson alienated the Democratic Unionist Party by striking a deal which leaves Northern Ireland effectively in the EU single market, but also the UK customs area, to ensure Great Britain could enjoy a looser relationship with Brussels after Brexit while maintaining a soft Irish border.
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De Rynck refused to respond to Johnson’s comments at prime minister’s questions on Wednesday when he was asked by the DUP’s Jefferey Donaldston whether his promise of no checks meant there would “continue to be unfettered access for Northern Ireland businesses to the UK single market” and vice versa.
Johnson replied: “Emphatically it does.”
De Rynck said: “I won’t dwell on comments I haven’t seen.
“The situation is clear - as of January 2021 the withdrawal agreement contains legally binding commitments, and the protocol is very clear that UK authorities will be in charge, if you are talking about goods flows from Great Britain into Northern Ireland, for the application of the customs codes of the European Union and to ensure that products that enter comply with single market standards of the EU, be it food, agri-food, industrial products and what have you.
“That’s a very clear commitment and the challenge for 2020 will be to work with the UK authorities.”
He added: “There are clear commitments on the UK which are legally binding.”
De Rynck pointed towards mechanisms in the Brexit deal for resolving disputes when asked what sanctions the EU could take, including the so-called “joint committee”.
He also suggested the UK could lose international standing if it breached the withdrawal agreement, the legislation for which passed through parliament on Wednesday.
“It’s the first major international agreement for Brexit Britain,” De Rynck said.
This article originally appeared on HuffPost.