It could see the 8pm hospitality curfew disappear as early as tomorrow.
NPHET has approved the easing of almost all Covid-19 restrictions with Cabinet Ministers meeting later to agree a timeline.
It's expected the hospitality sector, including nightclubs, will return to normal opening hours over the coming days.
Relief and jubilation among Cabinet Ministers last night as the NPHET letter arrived, with one saying it felt like a weight lifted off the shoulders.
Public health officials have recommended a sweeping lifting of Covid restrictions.
That includes ending early closing times for hospitality, including nightclubs; removing capacity limits at live events and matches; and scrapping the need to have a Covid pass to enter a bar or restaurant.
The only measures likely to remain are mask wearing in shops and on public transport, Covid passes for travel, some special guidance for schools and the test, trace and isolate system.
Health officials also greenlit a phased return to the office for workers.
NPHET hasn't set out a timeline for Government, leaving that for politicians to decide today.
Ministers say they have no intention of hanging about, but some legal regulations do need to be unwound.
Sources left open the idea last night that normal trading hours for hospitality could return from tomorrow, with nightclubs also opening.
If not tomorrow Monday was the other date being discussed.
However there's a belief it will be impossible to police a curfew this weekend now the contents of the NPHET letter are public knowledge.
The Government party leaders meet this morning; the full Cabinet will discuss things in the afternoon; and Taoiseach Micheál Martin plans to address the nation at 6pm.