In an article published by the Belfast Telegraph to coincide with his visit to Northern Ireland, the prime minister said the Protocol was out of date as it was written before the UK’s free trade deal with the EU, as well as the pandemic and the war in Ukraine.

“For there even to be a question about the fast availability of medicines or medical testing in Northern Ireland – between two constituent parts of the same National Health Service – is incompatible with the post-Covid era,” he wrote.

He said there was a need for “genuine dialogue” with the EU and called for a “shared objective … to create the broadest possible cross-community support for a reformed Protocol in 2024.”

Mr Johnson added: “I hope the EU’s position changes. If it does not, there will be a necessity to act. The government has a responsibility to provide assurance that the consumers, citizens and businesses of Northern Ireland are protected in the long-term.

“We will set out a more detailed assessment and next steps to Parliament in the coming days, once I return from discussions with the local parties.”

Last week, the UK government’s chief law officer gave the go-ahead for unilateral action on the Protocol on the basis that it would no longer be in breach of international law because it is causing “societal unrest”.