Business groups in Northern Ireland say Stormont's strategy to stop the spread of COVID-19 has failed.
This will be Northern Ireland's fourth lockdown and it will be imposed on St Stephen's Day.
The Stormont Executive has decided to close non-essential shops and restrict the hospitality sector to takeaway only.
In the first week of the lockdown, households will not be allowed mix and people won't be able to leave their homes after 8pm.
Head of Belfast Chamber, Simon Hamilton, who is a former DUP Minister, said the lockdown strategy has failed and a new way needs to be found to deal with the crisis.
He said: "That we're now entering another period of severe restrictions is a massive failure, a reflection of the Executive's inability to chart a different course, and businesses and thousands of jobs are going to the collateral damage.
"We now need to know the actions are expected to take over these six weeks to stave off future lockdowns.
The new restrictions come amid intense pressure on the health service, with 460 COVID-19 inpatients in hospitals there.
Now, ambulance crews from the Republic are to be drafted in this weekend, to help their colleagues in Northern Ireland.
Medical Director of the Ambulance Service, Dr Nigel Ruddell, issued a warning about spreading the virus over Christmas.
He said: "At a time of year when we all want to mingle I think if we're responsible we can limit the impact on the health service, not just for the number of COVID patients but the other patients who need those services, who need those ICU beds."
The measures are set to be reviewed after four weeks.
In the Republic, NPHET has recommended that restaurants and gastropubs should close after Christmas while the number of households allowed to mix should be reduced.
the Taoiseach said there is a "very strong likelihood" that the hospitality industry will be hit by further restrictions before the New Year.
