Women are being encouraged to stock up on free morning-after pills to keep with their headache tablets in case they become pregnant over Christmas.
Critics warn the scheme will encourage women and even young girls to engage in casual sex.
Listen to a Christian Institute spokesman debate the issue on BBC Radio
The British Pregnancy Advisory Service (BPAS), one of Britain’s leading abortion providers, is promoting the scheme through an advertising campaign that has been dubbed “sleazy”.
The caption, under a picture of a woman in a mini skirt cavorting with ‘Santa’, says: “Santa only comes once a year… but that’s all it takes.”
It adds: “In the heat of the moment it’s easy to get carried away with the festive spirit.”
The news comes as new abortion figures this week showed that the annual toll for England and Wales has now topped 200,000. Pregnancies terminated with the morning-after pill are not counted.
BPAS says it is expecting an increase in abortion referrals after Christmas, following a 25 per cent jump last January.
It says women should keep emergency contraception with their headache pills in preparation for the festive season, when chemists will be closed.
Ann Furedi of BPAS said: “It’s easy to get carried away, which is why we advise women to back up their birth control by keeping the morning-after pill at home.
“You don’t wait until you get a headache to buy your pain relief, why wait until you’ve risked pregnancy to get the morning-after pill?”
But Mike Judge, of the Christian Institute, said: “Having a morning-after pill beside your headache pills says Christmas is all about booze and sex.”
He added that the morning-after pill can cause an abortion by stopping the embryo from implanting.
“This will only mask the abortion figures,” he said.
Norman Wells of Family and Youth Concern said: “Studies have consistently found no evidence that advance supply of the morning-after pill reduces the rate of unintended pregnancies or abortions.
“In fact, when another abortion provider operated a similar scheme in the runup to Christmas, they subsequently reported their busiest ever January for abortions.”
John Smeaton, national director at the Society for the Protection of Unborn Children, said: “It is a despicable ploy which threatens unborn children, promotes promiscuity, endangers public health and insults the child-centred meaning of Christmas.
“This style of promoting the morning-after pill will have an adverse effect on many young and vulnerable women. It will encourage men to see females as sex objects, who can be exploited without responsibility for the consequences.”