Health Minister Stephen Donnelly will address the Dáil later today on his contacts with the Chief Medical Officer over the weekend.
Tánaiste Leo Varadkar said that Mr Donnelly will take questions from the opposition on the matter after Dr Tony Holohan said that he had spoken to the minister before Sunday's Nphet meeting.
Mr Varadkar said that the events of Monday, when he sharply criticised Nphet over the process by which the recommendation was made, were "a distraction".
However, he said that he had "never said a bad word" about Dr Holohan, who returned to his role on Sunday.
Mr Varadkar denied that he had heard about the potential lockdown via the media, saying that he had first heard about Nphet's recommendation when a letter was sent at 8.30pm on Sunday.
"I was informed on Saturday, as was the Taoiseach and the leader of the Green Party, that a Nphet meeting was called for Sunday. There was not a suggestion, not even an inkling, that level 5 was being contemplated for Sunday."
Sinn Féin's Pearse Doherty accused Mr Varadkar of "playing the man and not the ball", but the Tánaiste dismissed this as "trying to start the blame game".
The opposition has questioned whether the Government knew that Nphet was planning to recommend a lockdown before the letter was sent after Dr Holohan said that he had expressed his concerns to Mr Donnelly before the meeting.
Earlier today, Labour leader Alan Kelly called for full clarity on who knew what and when.
"We need details in relation to what happened over the weekend, because there are questions here about competency and capacity. And that is the most serious issue for me.
"Did the minister ask him on Saturday or Sunday morning: ‘Is what you’re saying to me so serious that we could end up at level 5? Because if so, and if that is potentially the outcome, then I need to communicate that across government, so we can prepare for it'."
A spokesperson for Mr Donnelly said that he had spoken to the Taoiseach after all of his conversations with Dr Holohan.
"Minister Donnelly informed the Taoiseach on Saturday afternoon that a Nphet meeting would be held on Sunday arising out of concerns about escalating case numbers.
"The minister for health and CMO spoke before and after Nphet's meeting on Sunday. Before the meeting, they discussed the deteriorating epidemiological situation. After the meeting, the minister was informed for the first time that Nphet recommended a move to level 5.
"The minister and Taoiseach communicated after both conversations between the minister and CMO on Sunday."