Ministers and spokespeople in Dublin have been instructed to “go dark” and refrain from commenting on the Conservative motion of no confidence in British prime minister Theresa May.
However, it is clear the Irish Government hopes Mrs May wins strongly this evening and goes on to gain the backing of the House of Commons for the Withdrawal Treaty.
Mrs May will face a vote of confidence in her leadership on Wednesday evening after more than 48 of her MPs wrote to the chairman of the backbench 1922 Committee calling for a challenge.
The prime minister will address Conservative MPs at 5pm, and voting will take place in a secret ballot between 6pm and 8pm, with a result expected before 10pm.
One Irish Government source speculated that if Mrs May wins well in the vote, Conservative waverers might rally behind her, while EU leaders could be prompted to give her concessions to make a Commons vote on the deal easier to pass.
Other sources say this is an optimistic view - and argue that even if she wins, Mrs May will still face a rump of Brexiteers on the Tory benches that will never support the deal, and that with Labour eyeing a general election, she will still be unable to win a Commons vote on the treaty.
However, Irish sources say a win for Mrs May would make declarations or statements from EU leaders - to the effect that the EU has no wish to keep the UK in the backstop indefinitely, or even for a long period of time - likely at the summit that begins in Brussels tomorrow.
EU leaders - including the Taoiseach, German chancellor Angela Merkel and the president of the European Commission - indicated yesterday a willingness to offer the UK “assurances” to help her domestically.
“They mightn’t help her win a vote in the Commons the first time. But they might help win one after Christmas,” said one Irish source.
If Mrs May is defeated tonight, EU leaders are likely to harden their position. It will mean that hard Brexit planning will accelerate significantly. However, Irish sources also say the time needed to elect a new Conservative leader - at least two months - would mean an extension or suspension of Article 50 would become more likely.
Whether London seeks such an extension, however, would ultimately depend on who the new Conservative leader is. Dublin believes defeat for Mrs May makes no deal more likely - but also makes no Brexit more likely. The chances of a middle ground soft Brexit would recede.