British Prime Minister Theresa May has told the European Union that the United Kingdom will not accept its proposals to deal with one of the thorniest issues in Brexit talks - the issue of the Irish border.
Democratic Unionist leader Arlene Foster welcomed her to the famous landmark, which sits close to the nearly invisible frontier between Northern Ireland and the Irish Republic.
"Guarantees were given in the Joint Report between the British Government and the European Union in December that there would be no diminution of rights as a result of Brexit, on the rights of people resident here and that the Good Friday Agreement would be protected".
And Sinn Fein say the Irish government must insist that the backstop agreed last December is translated into legally binding text.
Mrs Foster, whose 10 MPs prop up the prime minister's minority government at Westminster, said Mrs May would hear of the challenges and opportunities presented by Brexit.
As part of this, the Irish government plans to hire 1,000 customs officers and veterinary inspectors at its ports and airports over the next year.
Stating her determination to complete what we have started in Brexit talks, Mrs May will say: We can negotiate a new relationship with the European Union that works in our mutual interest.
Mrs May has repeatedly voiced her opposition and on Friday is due to do so again, saying: "The economic and constitutional dislocation of a formal "third country" customs border within our own country is something I will never accept and I believe no British prime minister could ever accept".
He said: "We are preparing for a change in the rules of trade between Britain and Ireland in January 2021".
Following a meeting with Barnier, new UK Brexit secretary Dominic Raab rejected suggestions the UK's position "hangs by a thread", and said "we're getting ready at home for the domestic preparations that we're making".
May's visit follows sustained criticism over her failure to visit the border, unlike the EU's Brexit negotiator, Michel Barnier, who has visited it twice.
"You say the government couldn't have been clearer on its position, however it has created huge uncertainty in Northern Ireland, it has actually now become a separate issue".
She also appeared to respond to Johnson who reiterated in his resignation speech earlier this week that "technical solutions to make customs and regulatory checks remotely" existed.
Brexiteer Commons Leader Andrea Leadsom put some pressure on Mrs May's plan, saying the European Union must be told the Chequers blueprint, which has divided the Conservative party, is the "final offer" rather than an opening gambit.
She told The House magazine: The EU has simply not taken us seriously so far in terms of the future agreement.
She will say the deal will put the United Kingdom on the way to "a prosperous future, protecting jobs and boosting prosperity" at the same time as honouring the 2016 referendum result, adding: "I am passionate about that brighter future and the possibilities that are within our grasp". "Clear UK commitments were made on this in Dec+March".
"I still think that's very unlikely".