Taoiseach Leo Varadkar is set for the briefest of showdowns with the British prime minister today as the Brexit chaos moves to Dublin.
Boris Johnson will bring his demands for the backstop to be scrapped directly to Government Buildings - but will be swiftly told such a move is not an option.
He will then fly back to London and make a second attempt in less than a week to cause a general election.
Mr Varadkar is not expecting a big breakthrough in this morning's talks but said he sees the meeting as "an opportunity to establish a relationship to see what common ground might exist".
He argued UK claims that a deal is close were "a very optimistic assessment of where we stand".
"If we come to an agreement, that will happen most likely in October at the EU summit," he said
While Ireland doesn't negotiate directly with the UK on Brexit, the two leaders can discuss potential alternatives to the backstop.
The UK is toying with the idea of an all-Ireland system of sanitary and phytosanitary (SPS) checks on agricultural products - but Mr Varadkar said yesterday this would only remove the need for around 30pc of border checks.
"It's not enough on its own. We would need a single Irish economic zone, to cover more than agriculture and food," Mr Varadkar said.
Asked if he would consider a return to earlier ideas of Northern Ireland specific solutions, the Taoiseach said this was something Ireland had always been open to.
"It will be interesting to see whether we could find some common ground on a Northern Ireland-specific solution, but I will have to judge that," he said.
Another week of Brexit drama is predicted after a senior member of the UK cabinet, Amber Rudd, became the latest Tory Party MP to resign. She said the UK government was not focused on achieving a deal, leading her to conclude they want to leave the EU without one.
Two ministers said Mr Johnson was determined to "keep to the plan" to leave the EU by October 31 with or without a deal to ease the transition.
The prime minister's strategy to leave "do or die" by that deadline has been shaken by recent events, which have prompted critics to describe him as a "tin pot dictator" and deepened uncertainty over how Britain's 2016 vote to leave the EU will play out.
He has lost his government's majority in parliament, expelled 21 rebels from the party and failed to force through a new election. Then his own brother quit, saying he was torn between family loyalty and the national interest.
Mr Varadkar indicated that no matter how much pressure comes from the UK, he will not compromise on the backstop. He suggested that even if that issue were resolved there is no evidence that the House of Commons would pass the Withdrawal Agreement.
"The situation in the UK is very fluid at the moment, Prime Minister [Theresa] May with a parliamentary majority was unable to get a deal ratified through the House of Commons. Prime Minister Johnson doesn't have a majority so I'll be asking him how he can convince us, Ireland, the EU, that he actually is capable or has the votes to get a deal through," Mr Varadkar said.