As popularity contests go, it's pretty unusual: a US entrepreneur is selling condoms featuring presidential hopefuls John McCain and Barack Obama.

Benjamin Sherman, who set up the company Practice Safe Policy, said that while the election campaign is a serious matter, he wanted to have some fun with it.

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The condoms' twin websites urge politically-minded shoppers: "These are uncertain times. The economy's a ball-buster and the surge went flaccid, but now there's McCain/Obama condoms, so get up get in and finish the job!"

The McCain condom, which boasts that it is "approved for veterans" carries the slogan "Old, but not expired".

'Use with good judgement'

Republican White House candidate Mr McCain, 71, served in the military in Vietnam, and was held as a prisoner of war there for many years.

According to the website, McCain condoms are "battle tested, strong and durable, for those occasions when you just need to switch your position!"

The Obama condom implores buyers to "Use with good judgement", and its website asks "who says experience is necessary?".

The site includes a 'testimonial' from an apparent fan - Jorge, 36, from Texas, who claims: "Obama condoms are just what this country needed. I always have them on hand for those important 3am calls."

While the company can't guarantee the condoms are 100 per cent effective, it says it's certain "that without wearing one, there's likely to be an Obama-Mama in your future".