Armed with child-friendly stickers, web-savvy promoters and chocolate figurines, the "Santa-Free Zone" movement says it is gathering steam this year against what it calls the hollow commercialisation of Christmas.
Launched by a German Catholic priest in 2002, the campaign aims to knock Santa off his pedestal and replace what they see as a cheap, American import with the real thing: Saint Nicholas.
"The movement is intended to raise awareness of the fact that the consumption-oriented Santa launched by the Christmas gift industry has very little to do with the holy bishop Saint Nicholas," said Christoph Schommer of the Catholic aid group Bonifatiuswerk, which is rallying the opposition to Santa.
The group launched a new website this year in time for the Christmas shopping season that lays out the stark differences between Santa and the real Saint Nick, and is drawing 12,000 unique hits per month from around the world.
Schommer said the downturn in the global economy had already muted the shop-till-you-drop mood that usually reigns at Christmas, and reported rampant interest in their Santa-Free Zone stickers and Nicholas chocolates in Germany, the rest of Europe and North America.
"There are several interesting parallels with the financial crisis, which also shows that material wealth is ephemeral," he said. "Investing in stocks can make your money disappear in a flash, but the value that Saint Nicholas stood for – that giving to others makes you richer and not poorer - is something that endures."
Saint Nicholas, an actual historical figure, was the fourth century Bishop of Myra in today's Turkey whose legendary modesty and generosity led him to give gifts in secret.
His most famous story tells how he saved three girls whose impoverished father wanted to sell them into prostitution. Nicholas, who had inherited a fortune from his father, left three lumps of gold over three nights in their room while they were sleeping.
Catholics and Orthodox Christians in much of the world still celebrate Saint Nicholas Day, usually on December 6, as a festival for children, who receive chocolates in their shoes when they leave them out overnight.
But Saint Nicholas has long been upstaged during the holiday season by the ho-ho-ho-ing Santa Claus, or Father Christmas in Britain and Canada, and activists would like the saint to reclaim the Yuletide throne.
Santa's red fur-lined suit, chubby mid-section and fluffy white beard are all thought to be inventions of ad-men at Coca-Cola, which came up with the grandfatherly figure for a campaign in the 1930s.
Opponents say Santa has cheapened Christmas by reducing a celebration of Christian values to a decadent and deeply dissatisfying display of greed.
But the Saint Nicholas camp also refuses to be dismissed as a bunch of Bah-Humbug curmudgeons. "We are doing the whole thing with a twinkle in our eyes – we aren't trying to take Santa away from anyone. But we want to make clear who the original Father Christmas is," Schommer said.
"Nicholas promoted values such as solidarity, loving thy neighbour, sharing what you have and the bushy-bearded Santa does just the opposite - he's a pack horse of consumer society, nothing more."
Protestants have also joined in promoting Nicholas over Santa Claus as a more fitting symbol of Christmas. The Lutheran Church put out a pro-Nicholas manifesto this month titled "How a Holy Legend Turned Into an Advertising Gag".
"'Jack Frost' from Russia and the 'Weihnachtsmann,' 'Father Christmas' and 'Pere Noel' were superimposed on the image of the bishop from Asia Minor by clever advertising strategists," it said. "That is how the charitable miracle-maker who helped young people in need degenerated into the giver of presents big and small."
The Santa-Free Zone group has handed out 100,000 stickers in six years emblazoned with a jolly fat man in a circle crossed through with a slash, like a no-parking sign, on high streets and at Germany's ubiquitous outdoor Christmas markets.