Lord Frost is to dramatically escalate the war of words with Brussels over the Northern Ireland Brexit deal – as he sets out new plans to rewrite the 24-month old accord.
The UK's Brexit minister will give a speech in Lisbon on Tuesday afternoon admonishing the EU for not listening to British demands.
And the UK's chief negotiator will present a new legal text to Brussels with concrete plans to amend the deal.
His intervention comes after a very public spat with the Irish foreign minister in which Simon Coveney accused Lord Frost of deliberately trying to torpedo EU-UK relations by being unreasonable.
Mr Coveney said demands by the UK to eliminate a role for the European Court of Justice were "a new 'red line' barrier to progress, that [the UK] know EU can’t move on".
In a sassy series of tweets the UK's Brexit minister said he preferred "not to do negotiations by twitter".
The UK wants to change the Northern Ireland Brexit deal it negotiated because it is causing disruption to trade with the rest of the UK.
But there is little appetite in EU capitals to seriously renegotiate the treaty, which was struck after years of painful negotiations with both Theresa May's and Boris Johnson's governments.
The EU is expected to set out its response to UK plans on Wednesday.
Maros Sefcovic, the EU's Brexit lead has said one of the UK's demands, removing the ECJ's role from the deal, would cut Northern Ireland off from the single market.
But ahead of the crunch point Lord Frost will claim: “Without new arrangements in this area, the protocol will never have the support it needs to survive.”
Lord Frost is expected to tell his audience in Lisbon that the relationship with the EU is “under strain”.
“No one should be in any doubt about the seriousness of the situation,” he will say.
“That is why we are working to reflect the concerns of everyone in Northern Ireland, from all sides of the political spectrum, to make sure that the peace process is not undermined.
"The EU now needs to show ambition and willingness to tackle the fundamental issues at the heart of the protocol head on.”
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