Liz Truss will make a major statement to MPs on Tuesday outlining a law to override parts of the post-Brexit deal on Northern Ireland, Downing Street has confirmed.
The Prime Minister's official spokesman said that she would set out the Government's rationale for using domestic legislation to make major changes to the deal signed up to by Boris Johnson.
Officials have denied that the Foreign Secretary wants to "rip up" the Northern Ireland protocol and insisted that she wants talks with the European Union to continue.
Ms Truss is not yet expected to publish any draft legislation, giving weight to the argument that she only wants to retain the option of unilateral action as a negotiating tool.
One insider told the Sunday Times: "We want a weapon on the table, we don't want to use it. It's like the nuclear deterrent".
Boris Johnson is holding emergency talks with Northern Ireland's political leaders today in a bid to break the deadlock caused by the post-Brexit trading arrangements.
The Prime Minister was booed and jeered by around 200 people, some holding banners reading "Back off Boris. Protect the Protocol", as he was driven into Hillsborough Castle.
Brussels has warned that unilateral action would represent a clear breach of international law - and could result in a trade war with the UK.
Ireland's foreign minister Simon Coveney suggested the whole UK-EU trade deal - the TCA - could be jeopardised if the UK takes unilateral action to tear up the protocol.
He told reporters in Brussels: "This is a time for calmness, it's a time for dialogue, it's a time for compromise and partnership between the EU and the UK to solve these outstanding issues.
"If that is the approach taken by the British Government then we can make significant progress and we can make progress quickly to respond to the concerns of both the business community and the unionist community in Northern Ireland.
"That alternative is unilateral action which means tension, rancour, stand-offs, legal challenges and of course calls into question the functioning of the TCA itself."
The UK has rejected a series of compromises put forward by Brussels last October to cut paperwork and checks on goods entering NI from Great Britain, suggesting they would make the situation worse.
Downing Street is expected to set out changes it wants to make through domestic legislation instead - which could take up to a year to get through Parliament.
These include a green lane for trusted traders to speed up customs checks and giving the Chancellor the power to cut VAT in NI in line with the rest of the UK.
The PM's official spokesman told reporters: "We believe the protocol, as drafted, allows for further negotiations, improvements and enhancements to be made, to facilitate properly, to work properly for the long term.
"That's what we want to do. We want significant changes to how the protocol is being enforced and we think there is sensible flexibility that was envisaged when it was drafted.
"We think there is a sensible landing spot within the protocol, and that's what we want to see."
The UK has so far resisted invoking Article 16, part of the NI protocol agreement, to suspend parts of the deal, although No 10 said: "We believe the conditions have been met".
Northern Ireland's institutions have been plunged into crisis with the DUP refusing to re-enter a devolved government in protest at the 'Irish Sea border' in the protocol.
Mr Johnson claimed the UK would have a "necessity to act" if the EU is unwilling to reach a compromise but stressed the Government remained open to "genuine dialogue" with Brussels.
In an article in the Belfast Telegraph, he claimed he had no plans to simply rip up the trading arrangements.
“Those who want to scrap the Protocol, rather than seeking changes, are focusing on the wrong thing,” he wrote.
“There is without question a sensible landing spot in which everyone’s interests are protected... Let us make it work.”
