Dr Sentamu accused secularists and atheists of undermining Britain's cultural traditions as he reflected the growing fury of church leaders over reports of companies banning Christmas decorations and schools leaving Jesus out of nativity plays.
"Aggressive secularists are trying to pretend that it is possible to enter into the true meaning of Christmas by leaving out Jesus Christ," he said.
"The person who is at the heart of the celebration is totally excluded. This really is a case of throwing out the baby with the bath water, or in this case throwing out the crib at Christmas."
The Archbishop continued: "This aggressive brand of secularism is trying to undermine the cultural traditions of this country by using flawed arguments about 'multi-faith, multi-culturalism' whilst at the same time trying to negate faith groups all together."
Dr Sentamu, a Ugandan-born former judge, added: "The aggressive secularists pervert and abuse any notion of diversity for the sake of promoting a narrow agenda. Meanwhile those other faith communities, who have stated categorically they are not offended by Christmas, know that if Christmas falls, they will be next.
"Why don't the aggressive secularists and illiberal atheists listen to the great wisdom of Sir John Mortimer, playwright and atheist, who writing in The Daily Telegraph on April 28, 1999, said 'Our whole history and culture in Europe is based on Christianity, whether you believe in it or not. Our culture is Christian; Shakespeare, Mozart - all that makes life worth living is part of the Christian tradition'."
A recent survey revealed that three out of four employers had banned Christmas decorations for fear of offending other faiths. The study found that 74 per cent of managers were not allowing any decorations in their offices this year.
Earlier in the week, Leader of the Commons Jack Straw said
suggestions that Christmas decorations in offices could offend staff of other faiths were "total nonsense".
"The simple truth is that my Muslim constituents and Muslim friends also wish to see Christmas celebrated," he told MPs.
"What is forgotten by people who come out with this nonsense is that those of the Muslim faith honour our prophets and those of the Jewish religion as much as they honour their own prophets." In October Mr Straw started a national debate when he revealed that he asked Muslim women to remove their full-face veils when they visited his constituency surgery.
