The Mayhew Animal Home in London has been strongly criticised for launching a controversial 'sex card' campaign to highlight the problem of pet overpopulation in the UK.

The postcards in question are based on prostitute calling cards which can be found inside phone booths in the capital. The set of six cards each feature an animal image and a racy strap line to grab people’s attention to take a closer read.

One of the cards – in a lurid pink – says ‘Wild Thing!!’ and ‘Who knows where I’ve been’ with the image of a fluffy young lapdog on the front.

Another one, in lime green, uses a photograph of a Staffordshire Bull Terrier with the headline ‘Pre op sexy beast – looking for no-strings attached sex, happy to share partners, likes it ruff’.

The charity in North-West London has chosen this attention-grabbing tactic to raise awareness about what happens to pets when left unneutered and they highlight the thousands of litters that die as a result of overpopulation.

But the campaign has drawn complaints from organisations like the Mothers’ Union, which described The Mayhew's action as ‘disappointing’.

Mothers’ Union spokesperson Fiona Thomas said: “It is extremely disappointing and we would urge any parents who see this in the public domain to complain to the Advertising Standards Authority

“Children are very important members of the public and have a right to be protected from sexualisation.

“The Mayhew has used sex to sell without any consideration of the age of the public they are targeting. Children are likely to see it and it is disappointing they think because other people use sex to sell, they can.”

Each card features a number on the front which goes through to a neutering hotline at The Mayhew and the reverse of the cards provides information about the serious side of the campaign.

Animal charities always notice a rise in welfare concerns during an economic crisis as pet expenses can no longer be afforded.

The Mayhew’s CEO, Caroline Yates, admitted the campaign was provocative but the charity was justified in taking such a bold stance.

“We are very frustrated at seeing countless unwanted and abandoned animals arrive at our rescue centre as a result of the chronic pet overpopulation crisis in this country,” she said.

“Charity campaigns about neutering awareness are simply not infiltrating into the population’s psyche and we are seeing rising numbers of stray animals every month. That is why we have taken a bold stance with a provocative campaign in order to make people really pay attention to one of the gravest animal welfare issues in this country.”

She added: “Hundreds of litters of kittens die all year round after unneutered domestic and stray cats breed and the young animals cannot survive the elements.

“We understand the recession is affecting everyone, but it is essential people consider whether they can afford a pet and not just purchase on impulse.

“The Mayhew offers free and low cost neutering appointments at our onsite clinic but our one charity can only do so much. We hope that this campaign will finally make pet owners and decision makers give this issue the serious attention it deserves.”

The six controversial cards are pictured below...