Christmas bubbles should be as small as possible, and people in Northern Ireland should consider forming them for 25 December only amid an "aggressive new strain" of Covid-19.
First Minister Arlene Foster, deputy First Minister Michelle O'Neill and Health Minister Robin Swann met with chief medical officer Michael McBride and chief scientific adviser Professor Ian Young on Saturday as rules were tightened in other parts of the UK.
Prime Minister Boris Johnson effectively cancelled Christmas for millions of people across London and south-east England after scientists said a new coronavirus variant is spreading more rapidly.