Wales will introduce new social distancing restrictions and close nightclubs from 27 December in a bid to slow the spread of the Omicron coronavirus variant.
The new tougher restrictions will also affect businesses and services and include extra measures to protect customers and staff – such as one-way systems and physical barriers.
The rules will also be changed to include a requirement to work from home wherever possible.
People are advised to follow five steps for a “safer Christmas”, before the new rules come into force.
First Minister Mark Drakeford said: “Delta will continue to be the main cause of coronavirus infections in Wales up to Christmas. But we are seeing cases of omicron increasing rapidly every day in Wales – and across the UK.
“We need a plan to keep us safe this Christmas and we need stronger measures to protect us afterwards, as we prepare for a large wave of omicron infections.
“Omicron poses a new threat to our health and safety. It is the most serious development in the pandemic to date.
“It is one we must take seriously. We will continue to put in place proportionate measures to protect people’s lives and livelihoods.
“This is a virus which thrives on human contact. Every contact we have is an opportunity for us to spread or catch the virus.”
The Welsh government has announced up to £60m will be available to support businesses affected by the new rules.
But news of the latest restrictions was met with dismay by members of the hospitality industry.
Michael Kill, CEO of the Night Time Industries Association (NTIA) said: “We are astounded at the actions of the Welsh government this evening, the consistent targeting of the nightclub and late night economy sector has gone too far.
“It is very clear that the Welsh government have purposefully placed restrictions on an industry with no supporting evidence.
“Nightclubs and the late night economy have been at the sharpest end of the pandemic, and have upheld the Public Heath Strategy within Wales for over 2 years, with closures and mounting debts.
“We have been placed in an untenable position and will now have no choice but to come out fighting.
“The sector will be considering it’s legal options following this announcement.”
It comes after the Welsh government cabinet met twice today to decide how to tackle the new variant, amid alarm at growing case numbers in the UK.
Dr Frank Atherton, chief medical officer for Wales, had previously advised the people to reduce their social contacts.
“We absolutely need to prioritize what we want to do at Christmas, for me, it’s about seeing family,” he told BBC Wales.
“It’s not about going to the pub, it’s not about going to a nightclub, it’s not about going anywhere that’s crowded or indoors.”
On Thursday, Wales reported a further 2,889 COVID-19 cases and 33 of Omicron.
This brings the total number of cases of the new variant in Wales to 95, a rise that is in part due to the change in how the strain is classified.
However, Dr Meng Khaw, from Public Health Wales, said “a rapid increase over the coming days and weeks is expected”.
Last week, health minister Eluned Morgan warned new restrictions were “likely” in the face of the “tsunami” of infections from the Omicron variant.
In last Friday’s three-week review, First Minister Mark Drakeford announced reviews would now take place weekly due to the threat posed by the Omicron variant.
He has urged people to get a booster vaccine and the number of vaccination clinics have increased with opening hours extended.