COAL is so clean and fresh that the prime minister brushes his teeth with it, Downing Street said last night.
Mr Brown said advances in coal technology meant it was now one of the cleanest substances on Earth, and an unrivalled remover of stains and scaling.
The prime minister is also storing all of his important documents in files made from coal, and using coal to remove dirty marks from his trousers and underpants.
A Downing Street spokesman said: "Coal not only removes stubborn stains and plaque, it's also an excellent source of clean energy. Especially when you set fire to it."
He added: "The prime minister loves the stuff and will often hand round large pieces of coal for ministers to lick at during Cabinet meetings."
Nikki Hollis, an environmentalist, said she was amazed to discover that coal was so clean and tasty compared to other forms of energy.
She said: "I stood next to a wind farm for a second and was covered in soot and ashes while the ground around me was strewn with dying baby rabbits and butterflies coughing up blood.
"Coal fired power stations do emit small amounts of CO2 but, thanks to new technology, you can just scoop it all up with a big spoon and put in a bucket."