The bra can heat to the same level as domestic heaters

The fluffy creation contains special pads filled with an eco-friendly gel that can be easily heated in a microwave or with a hot water bottle.

The design also includes a furry boa designed to double as a winter scarf.

Lingerie giant Triumph unveiled the bra months after PM Junichiro Koizumi urged Japan's office workers to ditch ties to save on air conditioning.

Being padded, the new bra packs a little more bulk than most regular designs, but the Japanese arm of Triumph insisted the look was more chic than sheep.

"We hope this will not only help prevent global warming but also provide a little fashion chic to the office," the company said in a statement.

The bra, which comes only in white, also features a pendant shaped like a chilli pepper dangling on its front.

Environmental support

The bra comes with matching shorts, but is not being offered for general sale. Instead the set is being viewed as a prototype product, the first step towards mass-producing eco-friendly clothing.

Japan's government is encouraging people not to set their domestic heating higher than 20C this winter, to reduce fuel consumption and conserve energy stocks.

During the summer, Mr Koizumi surprised Japan's traditionally well-dressed office workers by discarding his tie and urging his countrymen to do the same.

The drive to reduce air-conditioning use and thus greenhouse gas emissions was estimated to have saved enough power to supply 240,000 homes for a month.