British Labour Party leader Sir Keir Starmer has called on Boris Johnson to take personal responsibility for ensuring the Northern Ireland protocol works.
Mr Starmer has accused the British prime minister of putting “his own narrow interests” above those of the people of Northern Ireland.
In an opinion piece in the Times of London ahead of a planned visit to the North on Thursday, he said Mr Johnson's "reckless and foolish" approach to the Belfast Agreement was a risk to the peace process.
“I am sad to say that, after nearly three decades of slow but steady progress, we now have a prime minister who has put his own narrow interest above those of the people of Northern Ireland.
“We have a prime minister who has refused to take responsibility for his decisions, who is risking through his dishonesty, the stability of the peace process.”
“The prime minister personally negotiated the Northern Ireland Protocol and he has a personal responsibility to make it work” he added.
Mr Starmer called on the UK government to negotiate a deal on veterinary standards that could reduce the needs for checks in the Irish Sea.
“The recent extension of the grace periods was welcome, but that is not a durable solution,” he said.
“Over a quarter of all trade to Northern Ireland is currently subject to onerous ‘SPS’ checks, largely on food and agricultural products.
“The UK and EU need to work out a veterinary standards agreement to bring assurance to the people of Northern Ireland and benefit food exporters across the UK.
“The United States has been clear that a veterinary agreement is not a fundamental barrier to signing an FTA.
“The prime minister promised an agreement of this kind during trade negotiations with the EU. Yet, where countries such as New Zealand and Switzerland have succeeded, he failed.”
The Irish Government has said an agreement on SPS, similar to that between Switzerland and the EU, could eliminate 80 per cent of checks.
Mr Starmer said the he understood the concerns of the unionist community and businesses in the region about the barriers introduced by the protocol, but added that it is now time for solutions.
“These were problems that the UK Government knew were possible when they signed it. It is time for serious, practical solutions” he said.
The Labour leader said Northern Ireland should not be a partisan issue, noting the groundwork for the peace process done by former Conservative prime minister Sir John Major.
“Boris Johnson, though, cannot live up to that standard. His custody of the precious Good Friday Agreement has been designed to shore up his own party advantage. It is reckless and foolish,” he added.
Mr Starmer also took aim at Brexit negotiator Lord Frost, following a recent joint opinion piece with Northern Ireland Secretary Brandon Lewis in The Irish Times, which warned of "damage" to the Belfast Agreement if a "new balance" is not found for customs checks.
“It is hard to know whether Lord Frost is merely naive or deliberately provocative,” he wrote. “Whichever it is, the strategy of brinkmanship and picking fights in Northern Ireland is not the work of a serious politician.
“Does he not think the people of Northern Ireland deserve better than this?” – PA