Ireland's Taoiseach Mr Varadkar revealed schools, child care facilities, public offices and colleges are among the places that will close for more than two weeks in a bid to stem the virus, which has killed nearly 5,000 people and infected more than 127,000 worldwide.

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It comes as the UK moved officially to the "delay"coronavirus phase as the government concedes the deadly bug cannot be contained and Britain's death toll spiked to 10.

Today's move to delay was revealed after Boris Johnson chaired an emergency COBRA meeting to ramp up Britain's battle plan to the spiralling health crisis.

The government tonight advised Brits with mild symptoms such as coughs and colds, however mild, to self-isolate at home for seven days from tomorrow.

Anyone affected should stay at least two metres from anyone in their home and sleep alone, if possible - but schools will remain open.

Mr Johnson warned: "I must level with you. Many more families are going to lose loved ones before their time."

The UK's COVID-19 infection rate skyrocketed today, from 456 to 590 in 24 hours, the largest jump since the outbreak began.

IRELAND'S VIRUS BATTLE PLAN

Ireland's move will put pressure on Mr Johnson to announce similar school closures and bans on public events over here, but the PM's spokesman later appeared to rule out adopting the Republic's new measures across the border in Northern Ireland for now.

Coronavirus has infected 43 people and killed one person in Ireland so far, with a further 20 people diagnosed in Northern Ireland, where the restrictions do not apply.

Making a statement in Washington DC, Mr Varadkar announced a clampdown on indoor gatherings of more than 100 people and the cancellation of outdoor gatherings of more than 500 people.

People should reduce social interactions, with the public and businesses needing a "sensible, level-headed and responsible approach during this difficult time", he added.

Staff are being urged to work from home if possible as the lockdown comes into effect from 6pm today until March 29.

Mr Varadkar said: "It is going to involve big changes in the way we live our lives and I know I'm asking people to make enormous sacrifices, but we're doing it for each other.

"Our economy will suffer but it will bounce back.

"Lost time in school or college will be recovered and in time our lives will go back to normal.

"Ireland is a great nation, we're great people, we've experienced hardship and struggle before, we've overcome many trials in the past."

He added: "You can all play your part by handwashing, coughing or sneezing into your elbow or tissue and seeking medical advice if you develop symptoms. This is now more important than ever."

FIRST DEATH IN IRELAND

Under the Irish ban, museums, galleries and tourist sites are among the public facilities that will close.

Mr Varadkar also said that plans were in place to "ensure supply chains will not be interrupted".

The first coronavirus-related death in Ireland was announced yesterday.

The victim, an elderly woman who was being treated in a Dublin hospital, had an underlying respiratory condition.

Dublin's St Patrick's Day celebrations have already been cancelled as the pandemic rips across the globe.

Mr Varadkar cautioned that meetings and teaching should be done remotely, but shops, cafes and restaurants would remain open and should practise social distancing.

Public transport will continue to operate with airports and ports open.

People arriving into Ireland will be advised on what to do if they have symptoms of the virus.

Anyone entering Ireland at ports or airports will be fully informed and asked to self-isolate if they are displaying symptoms, the Irish premier added.

Working from home will be encouraged but where people do congregate in offices break times should be "staggered".

But following Mr Varadkar's announcement Mr Johnson's spokesman appeared to rule out adopting the Republic's measures across the border in Northern Ireland immediately.

The PM's spokesman said: "We have been in regular dialogue with Irish counterparts.

"In terms of our own response, we have said that we want it to be a UK-wide response and we have been working with the four chief medical officers and devolved administrations."

The spokesman added: "We follow our own advice, they will do the same."

Anyone entering Ireland at ports or airports will be fully informed and asked to self-isolate if they are displaying symptoms, the Irish premier added.

Working from home will be encouraged but where people do congregate in offices break times should be "staggered".

But following Mr Varadkar's announcement Mr Johnson's spokesman appeared to rule out adopting the Republic's measures across the border in Northern Ireland immediately.

The PM's spokesman said: "We have been in regular dialogue with Irish counterparts.

"In terms of our own response, we have said that we want it to be a UK-wide response and we have been working with the four chief medical officers and devolved administrations."

The spokesman added: "We follow our own advice, they will do the same."

Mr Varadkar's deputy Simon Coveney said of today's nationwide move: "Never before has such drastic action been taken in the face of a public health threat."

Meanwhile, Scotland could soon bring in a similar ban on outdoor gatherings as the country braces for its infection rate to spike, Ms Sturgeon revealed today.

Scotland's leader is now "minded" to ban gatherings of more than 500 people from next week, but said schools, colleges and universities would remain open for now.

Speaking after today's COBRA emergency meeting, Ms Sturgeon said: "The decision has been taken that we have now moved from a contain phase into the delay phase where the objective is to seek to slow down the spread of the virus, to reduce the numbers who will be infected at the peak, the number infected at any one time.

"From tomorrow, if you have symptoms that are indicative of coronavirus you should stay at home for seven days. There will be significant changes to people's experience."

Earlier, Ms Sturgeon warned of a "sharp rise in cases today" and of "further evidence of community transmission of Coronavirus".

She told First Minister's Questions: “The Health Secretary and I have decided this morning that we are minded that we will advise the cancellation, from the start of next week, of mass gatherings of 500 people or more."

Scotland's emergency services were likely to suffer higher than normal sickness absence rates in the weeks and months ahead, putting the NHS under "significant pressure", she said.

Speaking after this afternoon's COBRA meeting, Scots should isolate for seven days if they have a persistent cough or fever.

It came just hours after Denmark became the second European country to go into a total lockdown after Italy's draconian measures.

The Scandinavian country will shut all schools and universities and tell all employees with non-critical jobs to work from home.

Denmark has seen a ten-fold spike in cases, but no deaths.

Health Minister Magnus Heunicke described it as the "most dramatic increase seen in Europe".

Italy yesterday announced it was taking the extraordinary step to close all shops except pharmacies and food outlets in a desperate attempt to control the spread of coronavirus.

It comes as Italian health officials said the death toll today had risen to 827 from 631.

On Monday, Italian PM Guiseppe Conte extended a lockdown area already covering much of the north to the whole country.