The Brexit withdrawal agreement is dividing opinions in the UK after Theresa May's cabinet signed off on it yesterday.
The Taoiseach and EU leaders welcomed the deal, but the British Prime Minister faces a massive battle to get it passed in Parliament.
The 585-page withdrawal agreement was published yesterday and sets out how the UK will divorce the EU.
Key from an Irish point of view is the agreement on the backstop - the insurance policy to avoid a hard border on the island.
It is what comes into place if there is no trade deal reached between the EU and UK - and will not budge until there's an agreement.
It would see all of the UK in a single customs union, where trade rules and standards are kept so similar to the EU's that border checks will not be needed.
It is a significant win for the government, who got pretty much exactly what they wanted.
But the deal has several parts that may be unpalatable for unionists - Northern Ireland will be more closely tied to the EU than the rest of the UK.
And some goods coming from mainland Britain into Northern Ireland will be subject to checks as a result.
It is a massive uphill battle for Theresa May to now get this across the line in her parliament.
Many MPs are completely against it and she may face a vote of no confidence from Tory rebels today.
But she has insisted this is the best deal for the UK and European leaders have hailed it as a big step forward.
Ms May now enters the trenches again to build political support for the deal.
Last night, Mr Varadkar hailed Ms May for "honouring her promise" to avoid a hard border in Ireland post-Brexit.
The Taoiseach singled the Prime Minister out for praise as he made a statement in Dublin after the UK Cabinet backed the deal Mrs May has struck with the EU.
"No international negotiation gives one side everything it wants," said Mr Varadkar.
"For us the very notion of Brexit is unwelcome and brings adverse consequences.
"At the same time I want to acknowledge that these negotiations have been very tough and a difficult experience for everyone involved and, with this in mind, I want to acknowledge Prime Minister May's integrity in honouring her promise to protect the peace process and the Good Friday Agreement, and her commitment of avoiding a hard border.
"She has been true to her word."
Mr Varadkar has said the draft Brexit agreement could present economic benefits for Northern Irish business.
He said that if the trading arrangements envisaged in the draft agreement were embraced, they could "represent a genuine economic opportunity for Northern Ireland businesses, with unfettered access to both Great Britain and EU markets".
He added that the trading arrangements proposed in the draft text during the transition period are very welcome for all Irish businesses trading with the UK, with the UK land bridge facilitating the route from Ireland to mainland Europe.
Earlier on Wednesday, during Leader's Questions, Mr Varadkar moved to reassure Northern Ireland's unionist community, noting it was a "difficult time" and saying he was dedicated to restoring a powersharing executive in Stormont.
He added on Wednesday night that the government was no threat to their identity and was keen to solidify relations.
- Digital Desk & PA