A quarter of Christmas jumpers bought last year were thrown away or are unlikely to be worn again because people do not want to be seen in the same one twice, a survey has found.
Environmental charity Hubbub found that one in three under-35s buys a new Christmas jumper every year as the novelty fashion becomes an established part of the festive season.
The poll found that 29% of consumers think the sweaters - emblazoned with anything ranging from delicate snowflake patterns to flashing lights - are so cheap they might as well get a new one every year.
Hubbub's #GiveAKnit campaign is urging the public to "jazz up" their jumpers or pass them on as new figures suggest that £220 million will be spent on them in the run-up to Christmas.
It warned that the "incessant need for new" is harming the environment.
The Ellen MacArthur Foundation also recently exposed the scale of the waste generated by the fashion industry, and how the throwaway nature of fashion has created a business which creates greenhouse emissions of 1.2 billion tonnes a year - larger than that of international flights and shipping combined.
Hubbub is urging consumers to re-use a jumper they already own "and wear it with pride in the knowledge that you are helping the environment", swap with a family member or friend, or turn an uninspiring or moth-eaten top into a winter season statement piece.
Hubbub spokeswoman Sarah Divall said: "The Christmas jumper phenomenon is now a firm part of our Christmas celebrations in the UK and it has raised a lot of money for charity.
"However, it's also the perfect opportunity to reflect on our addiction to fast fashion which is having a devastating impact on the environment.
"I'd urge people to think twice about whether they really need to buy a new jumper this year. Instead let's dig out all those Christmas jumpers hiding away in wardrobes and swap with a friend or donate them to charity shops or even refashion something you already own."
:: Censuswide surveyed 3,000 UK adults in November.