Johnson has admitted that controlling Covid-19 was more challenging than he initially thought when he issued plans to ease restrictions.
However, he said preventing people from mixing with relatives and friends this Christmas would be “inhuman”.
“While it would not be right to criminalise people who have made plans and simply want to spend time with their loved ones, we are all collectively – across the UK, governments at every level – asking you to think hard and in detail about the days ahead and whether you can do more to protect yourself and others,” Johnson said.
At a press conference in Downing Street, he urged Britons to have a “merry little Christmas” by avoiding large gatherings. As the vaccine rollout is underway, he suggested that those who are planning to visiting elderly relatives, particularly vulnerable to the virus could delay until after they receive vaccine jabs.
Johnson`s move to press ahead with relaxation of Covid restrictions amid rising infections sparked controversy with concerns over the risk of worsening the crisis.
Labour leader Sir Keir Starmer accused the government of playing down the coronavirus pandemic by disregarding medical advice by proceeding with relaxation after ministers were forced to put London under the toughest coronavirus restrictions.
The Welsh government slashed the number of households who can form a “Christmas bubble”, from three to two, while Scots were advised to avoid overnight stays.