WWF-UK, the British branch of the international conservation group, has abandoned a policy of selling cards manufactured from recycled cardboard. Only one-fifth of the cards sold by the Royal Society for the Protection of Birds (RSPB) are recycled.
The charities say that they have "problems" with recycled cards, and that their supporters do not like them.
But other charities, such as Christian Aid and Cafod, sell only those cards made entirely from reused paper and insist that they have encountered no difficulties.
This year's WWF Christmas catalogue boasts: "Every item has been measured against environmental criteria so you can be confident that when you buy from the catalogue, you will be buying products that don't cost the earth."
Last year all its cards were printed on 100 per cent recycled paper, now they contain only 75 per cent reused materials. The rest come from cutting down trees.
The charity says that the decision to make the change "was not taken lightly", that it had had "a lot of problems with the 100 per cent recycled cards" and that it was using "the best environmental specification available to us". A spokesperson added: "Of course we must stick to our principles, but we must deliver Christmas cards."
The RSPB says it has had many complaints from its members about the recycled cards, even though the birds it is supposed to protect depend on trees. "We are trying to get the balance right between our principles and selling Christmas cards," a spokesman said.