The Brexit divorce between Britain and the EU is heading for more turmoil after the UK threatened to deviate from the deal struck in December.
London is seeking greater flexibility from Brussels over the Northern Ireland Protocol “sausage wars” that are threatening to sour relations.
Unless the European Union shows more flexibility an announcement on a significant change to the protocol could soon be made by David Frost, the British minister who leads Brexit negotiations.
"Things have got to change," Lord Frost told a parliamentary committee, saying barriers on goods moving between mainland Britain and Northern Ireland needed to be removed.
"We all know the protocol is not sustainable in the way it's working at the moment. All options are on the table."
He said that the east-west elements of the protocol were not working as well as the north-south, referring to the routes between Britain and Northern Ireland, and Northern Ireland to the Republic of Ireland.
"If the protocol is undermining the peace agreement then it's not doing its job," he said.
However, in a sign the UK was willing to remain flexible, he said a "durable solution" would be more likely with agreement.
Lord Frost will now present plans to Parliament on Wednesday alongside a new paper on Brexit. “We will set out our approach to the protocol in due course,” a government spokesman said.
However, any changes could jeopardise the delicate peace deal established in the province in 1998. Britain's intentions could also irritate US President Joe Biden who has strong Irish heritage and has been outspoken on threats to the Good Friday Agreement.
Unless the EU agrees to compromise, Brussels officials expect Britain to adopt unilateral measures using Article 16 of the protocol, a safeguard clause allowing either party to take unilateral measures if applying the protocol "leads to serious economic, societal or environmental difficulties that are liable to persist".
“It will be a plea for more talks with the EU combined with a threat,” a senior EU official told Reuters. “But we will not agree to the reopening of the Irish protocol.”
There are also concerns from Brussels that Mr Johnson will look to remove the European Court of Justice from the arbitration process.
The 63-page Northern Ireland protocol was introduced to avoid a so-called “hard border” of customs checks with the Republic of Ireland.
It effectively kept Northern Ireland in the EU's single market for goods and applied EU customs rules at its ports, creating a border in the Irish Sea with mainland Britain.
The move infuriated sections of the largely-Protestant Unionist community who fear it will jeopardise ties with the UK.
A potential deviation from the protocol would potentially have far-reaching consequences for Britain’s relationship with the EU, as well as stability in Northern Ireland.