The Good Morning Britain host described the fight against the pandemic as "our war" and urged the UK not to complain if Christmas does not go ahead.
"This virus has not got any less virulent," Mr Morgan said on the show on Monday morning.
"It doesn't understand rule of six, or Boris' idea of having Christmas Day off, as if somehow we can all amass on Christmas Day and then go back to the rules.
"If we miss Christmas Day as a country, if that's what we have to do, we have to do it.
"This is our war. I think people have to be realistic about that."
Last week, Boris Johnson warned that actions to stop a second surge of Covid-19 must be "tough now" in order to "protect" Christmas .
The Prime Minister said people have to be "both confident and cautious" and that it is "crucial" the country does not re-enter "some great lockdown again that stops business from functioning".
"Christmas we want to protect, and we want everyone to have a fantastic Christmas," he told the Sun.
"But the only way to make sure the country is able to enjoy Christmas is to be tough now.
"So if we can grip it now, stop the surge, arrest the spike, stop the second hump of the dromedary, flatten the second hump."
At a Downing Street press conference in early September, Mr Johnson said that he was "still hopeful" that Christmas could go ahead as normal.
But he suggested that this would require the "moonshot" of mass-testing, adding: "We are aiming for that. We are driving for that. As I have said…we cannot be 100 per cent sure that we can deliver that in its entirety."
It comes after a Tory minister said people should stop “whingeing about not meeting granny at Christmas” as much could change in the coming weeks.
Lord Blencathra was speaking in a debate on face covering regulations in England, in which he supported the measures in place and pressed the Government to simplify the rules on wearing face masks.
Separate Government rules which limit social gatherings to six people have caused concern for people about the impact it will have on their Christmas celebrations.
But Lord Blencathra said: "Please (health minister Lord Bethell) tell the media to stop whingeing about not meeting granny at Christmas.
"Christmas is three months away and anything can happen in the meantime."