The Archbishop of Canterbury will not deliver his Christmas Day sermon today.
Lambeth Palace said the Most Rev Justin Welby has been suffering from a "severe cold" for several days and decided this morning that he was too unwell to speak at the annual Canterbury Cathedral service.
A Lambeth Palace spokesman said: "The Archbishop of Canterbury, the Most Rev Justin Welby, is suffering from a severe cold and will, with great regret, no longer be preaching the sermon at Canterbury Cathedral this morning.
"The Dean of Canterbury, the Very Rev Robert Willis, will deliver a homily."
The full text of the Archbishop's address will be published on www.archbishopofcanterbury.org this morning as a Christmas Message, Lambeth Palace said.
He had been due to talk about how the true spirit of Christmas cannot be captured in fairytale endings, using the example of the First World War Christmas truce in 1914.
The Archbishop had been due to say: "The truce illustrates something of the heart of Christmas, whereby God sends his Son, that vulnerable sign of peace, to a weary war-torn world.
"The problem is that the way it is told now it seems to end with a 'happy ever after'.
"Of course we like Christmas stories with happy endings: singing carols, swapping photos, shaking hands, sharing chocolate, but the following day the war continued with the same severity.
"Nothing had changed; it was a one-day wonder.
"That is not the world in which we live, truces are rare."