Wales will go into national lockdown from midnight on Saturday, earlier than initially planned, after growing concerns about the spread of a new coronavirus strain.
The first minister said the situation is ''serious'' and the country will enter alert level four from midnight.
Rules had been due to be relaxed to allow people to celebrate the festive break with families from 23 to 28 December, however the rules will only be relaxed for Christmas day only - similar to England.
What are the alert level 4 restrictions?
The level 4 restrictions look similar to what Wales was put into in the original lockdown at the start of the pandemic and the fire-break which ended in November.
Non-essential retail, close contact services, gyms and leisure centres and hospitality will close.
Stay-at-home restrictions will also come into effect from midnight.
Only essential travel would be allowed - unless you have a 'reasonable excuse.'
People will be encouraged to work from home if they can.
Extended households would not be allowed, and you can only mix with those in your household or support bubble.
How does this affect Christmas?
The initial plans for a relaxation of rules from December 23-27 have been scrapped. Instead, no more than two households will only be able to meet on Christmas day.
The first minister confirmed it would be illegal to form a bubble with more than two households.
Following the emergency talks, Mr Drakeford said the Welsh Government had to ''respond quickly to the rapid changes.''
''Today has been one of those days when new information has required an immediate response. This afternoon, the Cabinet met to discuss this worrying new development in the pandemic and to hear the latest advice from our senior medical and scientific advisers, including the impact on our NHS.''
''The situation is incredibly serious. I cannot overstate this. We have therefore reached the difficult decision to bring forward the alert level four restrictions for Wales, in line with the action being taken in London and the South East of England.''
The Welsh Conservatives supported the decision. Leader of the party, Paul Davies MS, said he ''appreciated the need for more severe restriction.''
"I know that many people will be disappointed as they were looking forward to seeing their loved ones this Christmas, but in the face of the emerging evidence it is clear that Christmas bubble arrangements must change.''
The new strain, which has been linked to the faster spread of Covid-19 in the south of England, was identified in Wales earlier this week. The Welsh Government said they expect more to be identified.
Mark Drakeford said the strain is ''significantly more infectious and spreads more quickly.''
As of Saturday, more than 3,000 people have died with the virus in Wales. Rates of infection have increased in 20 of the 22 local authorities over the last seven days, with the seven-day rolling average now exceeding 1,000 cases per 100,000 in two areas.
Boris Johnson announced households in London and the south-east England will be banned from mixing over the festive period, while in the rest of England, three households will be limited to meeting indoors on Christmas Day only.
London and the south-east will also move into a tier 4 from midnight, with lockdown restrictions coming into force.