The Church of England has challenged the Royal Mail's move to issue festive stamps without a Christian theme.
Santa, a snowman and a reindeer are among the festive images on the Royal Mail's 40th set of Christmas stamps.
The church "regretted" Royal Mail's decision not to launch "Christian themed designs reminding people of the true meaning of Christmas".
The Royal Mail said it alternated its designs between religious and non-religious cards each year.
"It's about celebrating all elements of Christmas," a spokesman said.
Despite the rise of e-mails, more Christmas stamps are being sold now than ever before, according to the Royal Mail.
"Christmas cards are more personal and Christmas stamps mean they're festive on the outside and inside," a Royal Mail spokesman said.
The stamps will be available in two sizes reflecting a new price structure.
Under the new pricing system introduced in August, the cost of sending mail is based on the size, weight and thickness of items.
"People are getting used to the system and we have received some great feedback," the Royal Mail said.
The first edition of Royal Mail Christmas stamps was launched in 1966 with the design chosen from more than 5,000 entries in a competition for schoolchildren.
The new stamps are part of a larger collection of special editions which will include a 2007 set showing The Beatles' album covers.