New emergency legislation is to give the Welsh Government "draconian" powers to isolate and detain individuals.
First Minister Mark Drakeford said the law will give ministers powers not normally seen in peacetime.
It will allow senior politicians to prohibit mass gatherings, and close premises where they are happening.
Meanwhile the first minister defended the decision to test the health minister, Vaughan Gething.
Mr Gething is back at work after a period of self-isolation, after receiving a negative test.
The new legislation provides sweeping measures, for up to two years, to help UK authorities tackle the coronavirus outbreak.
It is a UK government bill, but has been produced in co-operation with the administrations in Scotland, Wales, and Northern Ireland.
To be introduced to Parliament on Thursday, the law is expected to come into force by the end of the month.
Ministers in Wales will be able to:
- take or keep people in quarantine, or direct a person to attend a designated place
- restrict or prohibit mass gatherings
- close premises
Mr Drakeford told a press conference: “The bill responds to the unprecedented difficulties that we face and is based on the need to reduce the rise in coronavirus on the one hand, and to free up public services... so they can be doing more at the front line.
“These are powers to be used if we reach a point where such draconian interventions in the lives of individuals are necessary."
What other powers will ministers have?
The first minister said the bulk of the powers are focused on freeing up resources so services can "respond more rapidly, more flexibly, to more urgent needs”.
Ministers will be able to instruct schools to close, or to remain open.
There are powers that would allow the redeployment of teachers to address shortages; to disapply standard ratios of staff to children requirements, and to allow people to return more rapidly to the workplace.
In health and social care the bill will allow ministers to state circumstances where DBS criminal record checks can be “disapplied”.
Mr Drakeford said it would allow someone who had a DBS check in one setting, to use it in another.
The legislation will aim to avoid delays in the recruitment of health or social workers to meet increases in demands, and provide indemnity cover for health workers during the pandemic.
Hours of crematoriums may be extended under powers to manage the number of deaths that the virus may cause.
The UK government says the measures contained within the coronavirus Bill, which will be examined by MPs on Monday, will only be used when necessary and have a time limit of two years.
Labour MPs are calling for a fresh vote on the legislation every six months, while Rhondda MP Chris Bryant said he will try to amend the bill to force parliament to vote every 90 days.
He told BBC Wales: "The government undoubtedly needs additional powers to be able to tackle coronavirus both in England, Wales, Northern Ireland and Scotland."
He added: "I don't think its right they should have those powers for two full years without ever coming back to parliament for further approval."
He said he would table an amendment to force the government to come back to the commons ever 90 days "to make sure those powers are still needed and still have the approval of Parliament".
Could Wales go into lockdown?
Amid speculation of further action to restrict movement in London, Mr Drakeford said there were no “imminent” plans for a lockdown in Wales.
“The measures we are taking already are the measures we are told that will have the greatest impact in stopping the rapid rise of the disease that otherwise would have taken place,” he said.
But he echoed comments from Prime Minister Boris Johnson that further measures are not being ruled out “should the evidence from the experts tell us that we need to do even more to keep the progress down so that the health service is able to cope”.
He said the public had been “ahead of the curve” in complying with the social distancing guidance. Mr Drakeford said the volume of cars on the roads in Cardiff was at a “very different order to this time last week”.
But he conceded that not everybody was following the messages.
“It is really important we go on making it clear to people this is a genuinely serious position,” he added.
NHS workers to be tested for coronavirus
He said health minister Vaughan Gething’s negative test for covid-19 was “good news for Wales".
Testing for coronavirus is being extended to front-line health workers, with potential to go further, but there is no wide-scale community testing taking place.
Explaining why Mr Gething was tested, Mr Drakeford said it was important everything was done so Wales can "have a health minister there to answer the questions that assembly members and opposition parties have over the way the government is making decisions”.
“Having your health minister at his desk able to be part of that decision making, able to be answerable to the Senedd… that puts him in a different position," the first minister added.