After hourslong deliberations, ministers voted on Tuesday to tighten the lockdown, shuttering schools and nonessential businesses, starting overnight Thursday for two weeks.
As part of the new measures, gatherings will be limited to five people indoors and ten people outdoors, only essential workers will be allowed to leave for work, and all professional sports activities will be canceled.
Israelis will still be prohibited from venturing more than one kilometer (0.6 miles) from home or stay at other households.
Prime Minister Benjamin Netanyahu on Tuesday told ministers that he now supports a Health Ministry request for the proposed tighter lockdown to start from Thursday and not Friday later as he originally suggested.
"We are in the midst of a global epidemic that is spreading at record speed due to the British mutation. It has reached Israel and is claiming many lives," he told a cabinet meeting to discuss the new tighter restrictions.
"We must immediately impose a full closure. I have no doubt that the government will approve it and the Knesset has to pass it immediately," he said.
Earlier Tuesday, Netanyahu and Defense Minister Benny Gantz announced that Israel would go into a full, tight lockdown from Friday - including the entire education system - after health officials demanded urgent action over the soaring coronavirus infection rate that has put COVID-19 wards across the country on the brink of collapse.
The country has already been already in its third lockdown for more than a week, with restrictions on movement, entertainment venues, shops and gatherings but schools still allowing some students to attend class in person.
But the number of cases has continued to climb, with 8,308 people testing positive for the virus on Tuesday - the highest number of daily diagnoses since September 30 and an infection rate of 7.7%.
The new restrictions were brought for government approval almost immediately.
"The British mutation is out of control," Netanyahu said as the cabinet met in Tuesday afternoon.
"Hospitals are already warning that we are entering a dangerous phase. The Health Ministry says that if we do not act immediately, we will lose many hundreds of Israelis.
"I call on all Israeli citizens to make one last effort - a general closure in combination with the vaccination campaign is how we will come back to life."
While the two leaders are in lockstep on the need for tighter restrictions, Netanyahu wants the closures to last until the infection rate has dropped dramatically and Gantz is backing measures for just 10 days.
The Health Ministry was pushing for the measures to take effect from Thursday and called for all shops - including supermarkets - to be closed every day from 7pm.
Israel's coronavirus czar Prof. Nachman Ash said earlier Tuesday that he backs the total shutdown of the education system and warned that any delay in implementing a stricter lockdown will result in the loss of human life.
"We are seeing the numbers go up every day, including serious cases," Ash said. "We have passed the threshold of 800 serious patients, which is a red line."
He said regardless of the government's decision, parents should not send their children to schools if they live in areas with a high infection rate.
"A child who brings the disease home infects others. We have seen quite a few such cases in recent days," he said.
Health Minister Yuli Edelstein and the ministry's public health chief, Dr. Sharon Elrai-Price, also held an impromptu press briefing earlier in the day to sound the alarm over the soaring infection rate.
"We need to reach a full lockdown, except for essential work, with a shuttered education system and zero gatherings," Edelstein said. "Not doing anything today will result in hundreds more dead and thousands more seriously ill."
He said it would be detrimental to Israel's accelerated vaccination campaign not to impose a full lockdown, since those who had already been vaccinated with the first shot might get still infected before they receive a second jab to develop higher immunity.
"Some of the [new] virus patients are elderly, who have already received the first shot of the vaccine," he said. "They were meters away from being saved. Today there are outbreaks in nursing homes, where the vaccinations have also been carried out. The ball is in the hands of the government," he added.
"When was the last time the public itself was asking us to close everything? The heads of local authorities and people on the street say to us, 'stop, impose a lockdown."
Edelstein also blasted young people who turn up to vaccination centers to get the shot without appointment. "There were criminals who tried to sneak in at the expense of the elderly and the sick. The phenomenon is unfortunate. There are no excess vaccines when there are only 2,000 [in each vaccination center]."
Elrai-Price said the majority of this country at the moment lives in either "red" or "orange" cities and communities.
"Even if we stop the spread, we know that the numbers will continue to rise. We are breaking the record for predicted number of serious patients. The number of serious patients is rising and creating a huge burden on hospitals."