The Taoiseach has said that from midnight last night until 12 April, everybody must stay at home except in specific circumstances.
Leo Varadkar made the announcement in an update on the Government's response to the coronavirus pandemic at a press conference at Government Buildings.
"Our country is rising to this challenge, and I'm convinced we will prevail," he said.
The specific circumstances include travel to and from work for essential work that cannot be done from home; to shop for food, household goods or collect a meal; to attend medical appointments, collect medicines and other health products.
Other exemptions include farming, the care of animals and leaving home for vital family reasons such as providing care for the elderly or vulnerable.
Mr Varadkar also said that people can leave their home for brief physical exercise, but only within 2km of their home. People must also adhere to physical distancing during this time.
He announced that during the two-week period, all public or private gatherings of any number of people outside a single household or living unit are prohibited, including social family visits that are not for vital reasons already mentioned.
And he said shielding or "cocooning" will be introduced for all those over the age of 70 and for specified categories of people who are extremely vulnerable to the coronavirus.
All public transport and passenger travel will be restricted to essential workers and people providing essential services.
The Taoiseach said that all visits to hospitals and prisons will cease with some exceptions on compassionate grounds.
He also said that travel to offshore islands will be limited to residents.
Gardaí say a high visibility operation is now under way involving thousands of officers.
They say they will intervene where people are not complying with measures and they have appealed to people and families not to attend popular spots for overly long periods, and if it is busy to leave.
The announcement comes after the National Public Health Emergency Team today announced three more coronavirus-related deaths, bringing the number of people who have died from the virus to 22.
It also confirmed 302 further Covid-19 cases, rising the total number of confirmed cases in the Republic to 2,121.
Taoiseach Leo Varadkar outlines further Covid-19 measures, says everybody must stay at home from midnight tonight until Easter Sunday, 12 April | Follow live updates: https://t.co/W2t5MvPevS pic.twitter.com/dx5HbeKts6— RTÉ News (@rtenews) March 27, 2020
'Radical actions' aim to save people's lives
The Taoiseach said the new restrictions are radical actions aimed at saving as many people's lives as possible.
"We are not prisoners of fate, we can influence what is going to happen next," he said.
Mr Vardakar said that as we enter this most intensive phase of restrictive action, the Government's emergency response will be ramped up.
Local emergency response will be led by local authorities who will bring together all the State agencies as well as local community groups, charities and volunteers to ensure all of our citizens get the help they need at this exceptional time.
"Freedom was hard won in our country and it jars with us to restrict and limit individual liberties even temporarily," the Taoiseach said.
"But freedom is not an abstract concept - we give it meaning every single day in the way we live our lives and the decisions we take willingly to protect our loved ones and colleagues.
"So I am asking people to give meaning to our freedom and liberty by agreeing to these restrictions, by restricting how we live our lives so others will live."
"I am asking us for a time to forego our personal liberties and freedoms for a greater cause and I am appealing to every man, woman and child in our country to make these sacrifices, not out of self-interest, but out of the love of each other, to begin each day knowing that every single imposition, every single inconvenience, every irritation, every lost opportunity will save lives and help our health service to cope."
The whole world is suffering during this pandemic and Ireland is no different, he added.
"What happens next is up to each and every one of us," he claimed.
"So show your support for our healthcare staff, show your support for everyone who is working in essential services or looking after vulnerable citizens, show you care for your family and friends. Stay at home."
The Minister for Health said that the Government is asking people to stand again with the frontline healthcare workers as they did last night.
"They are staying at work, so we need you to stay at home," Simon Harris said.
He said we have become so aware of what is happening in the rest of the world during this pandemic, but our personal worlds must shrink again.
He said we as a community and the Government will help older people to stay at home altogether.
"The situation is not going to get any easier in the days ahead, but we have to take the measures advised by our public health experts to give ourselves the very best chance to reduce the impact of this virus and save lives," he said.
"The time will come again when our life goes back to normal, when the distance we now have to put between us can fall away," he said.
The Taoiseach also said that there was not much more the Government could do beyond these measures to restrict the movement of people.
He said gardaí have extra powers to detain people and penalties can be imposed on people who breach the rules. However, he said, the best way it could be achieved was by people understanding why the measure are put in place and buying into that.
Mr Varadkar said that would be much more powerful than what our 15,000 gardaí can do, but they will be available to police it.
He said in addition to gardaí, the Government has the possibility of calling on the Defence Forces and the reserves if required.
In a statement, An Garda Síochána said that it has begun a "major nationwide policing operation" which focuses on supporting public compliance with public health measures over the weekend.
Following the Taoiseach's announcement, gardaí said that there will be high visibility patrolling by gardaí across the country over the weekend. They said that the operation is in place until 7am Monday morning.
Gardaí say that they will intervene where venues or outlets are not in compliance with the new restrictions, or where groups of people "are not adhering to recommended measures".
Garda Commissioner Drew Harris said: "It is vital that people adhere to the social distancing guidelines. This will reduce the spread of Covid-19 and save lives. The vast majority of people are complying with the guidelines and we want that to continue this weekend.
"By all of us working together, we can flatten the curve and keep our loved ones safe."
Chief Medical Officer Dr Tony Holohan says it is now important to spend two weeks to suppress the spread of Covid-19 in the community | Follow live updates: https://t.co/W2t5MvPevS pic.twitter.com/WgATxERG4D— RTÉ News (@rtenews) March 27, 2020
The Chief Medical Officer at the Department of Health has said now is the time to move to strengthen the measures further, and try to spend two weeks in really suppressing the transmission of the virus as much as is possible in the community.
Dr Tony Holohan said in 50% of Covid-19 cases identified, they have no links which show how the infection was picked up. "This tells us the virus is in the community," he said.
"We think in the early course of this infection, with the support that we've had from the public, that with these additional strengthening measures we can drive the infection back out of the community and into households," he said.
"And we can continue our public health advice to people who have symptoms to self-isolate for 14 days, to make contact with their GP and that their household contacts isolate with them.
"We think these measures, when we look at the number of contacts per case, will significantly interrupt the transmission of this virus, which is our objective and turn the infection, which is a community-based infection, into one which is a household-based infection," he claimed.
Dr Holohan said they think that can have an impact not only in the transmission of the virus but also in the progression of the serious infections which have resulted in intensive care admissions and ultimately feeding through into protecting and saving lives.
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