Health Minister Robert Swann reportedly warned Stormont colleagues that if action wasn't taken immediately, hospitals in the North would be overrun before Christmas.
He said otherwise, a full lockdown in mid-December would not be enough to prevent hospitals from becoming overwhelmed.
"I put that to the Health Minister, very bluntly, very clearly, and was told they were content that this was OK, that this was factored into the modelling which they had brought in front of us".
It is thought discussions will continue into Thursday evening, with ministers taking a brief adjournment until 18:00 GMT.
It is believed that is to allow health officials to take some of the minister's advice and put it into formal recommendations.
This time the DUP joined the other parties in supporting the steps.
From tomorrow, cafes, coffee shops, hairdressers and beauticians are allowed to reopen, while pubs, hotels and restaurants had been expected to re-open next Friday.
Until now, the executive has only advised against "unnecessary travel".
What are the new measures in Northern Ireland?
Two of the leading vaccines - Pfizer and AstraZeneca - have completed their final trials and are seeking authorisation.
It said this will be in line with allocations made through the Barnett Formula.
There were also 357 positive cases of the virus recorded since yesterday.
Meanwhile, there are now 429 people in hospital with coronavirus with 41 in ICU, 31 of whom are on ventilators.
Covid-19 related deaths: 79 more deaths as grim death total rises to 1,227Latest figures published today by NISRA show that 79 deaths involving Covid-19 occurred in the last week, from 7 to 13 November and the total Covid-19 related deaths figure has now reached 1,227.
The marked change in tone from the DUP is certainly significant.
The restrictions agreed by the executive late on Thursday are more severe than proposals that were vetoed by the DUP last week, prompting rivals to accused the party of a major U-turn.
The atmosphere around the executive table appears very different today, so far - with the potential that consensus could be reached by the five parties.
Ms O'Neill added: "We had to take these hard decisions but it came on the back of strong medical and scientific advice, and was necessary".
On Wednesday, Mr Swann said he would bring a range of options to ministers including restrictions and initiatives.
Robin Swann says the "stricter" measures are necessary to get Covid-19 under control and protect the health service.
Schools will stay open and "close contact" services can reopen on Friday 20 November, but then they'll have to close again after one week.
Sir Jeffrey said his party would "work with the health minister and other ministers in the executive to arrive at a consensus".
He urged people to "stick with us".
The Northern Ireland executive said last night (Nov 19) that all non-essential retail - which includes showrooms - must close from November 27 to December 11.