The Bolivian legislature has approved a Bill of Complaint filed by President Evo Morales’ government to withdraw Bolivia from the 1961 Single Convention on Narcotic Drugs in 2012 over its prohibition personal use, consumption, possession or cultivation of the native coca leaf.

In support of the measure, the government cited Article 384 of the Bolivian Constitution passed in 2008, which obligates the State to protect use of the coca leaf as a part of Bolivia’s ancestral cultural heritage and rejects the designation of coca in its natural state as a narcotic.

“It’s important to make this complaint for our people to continue practicing their culture,” said Foreign Minister David Choquehuanca following passage of the bill.

Bolivia has consistently called for change to the 1961 Convention since 2009. That year, it began a process to amend Article 49 of the Convention, which prohibited consumption of the coca leaf 25 years after passage of the Convention beginning in 2001. Its proposal for amendment was formally opposed by 17 other Convention signatories, including the United States, U.K., France, Japan, and Russia.

While major Western governments have long had no difficulty outlawing this indigenous regional practice, other governments have not been as supportive. The Chinese government has compared a ban on chewing coca in Bolivia to a ban on drinking tea in China.

Protection of traditional coca leaf-chewing, which dates back in the Andes over 3000 years, has been a priority for President Morales, who rose to prominence in Bolivia after leading a coalition of coca growers defending their right to grow the crop against U.S.-led eradication efforts. Although the UN Convention treats the coca leaf and processed cocaine the same, Morales and supporters of traditional coca growing reject the classification of the coca leaf as a narcotic with the popular campaign slogan, “Coca sí! Cocaína no!”

Andean communities have chewed coca for personal use and for public health purposes, citing traditional medicinal applications for the relief of gastrointestinal problems, respiratory ailments, and altitude sickness. A U.S.-blocked World Health Organization report in 1995 echoed these findings.

Bolivia’s withdrawal from the 1961 Convention, so long as it’s filed with the UN Secretary-General by July 1, 2011, will take effect beginning in January 2012. Although Bolivia’s formal complaint over the coca leaf ban will technically withdraw it from Convention compliance beginning in 2012, Bolivia has stated it voluntarily intends to continue complying with the drug trafficking and narcotics control sections of the Convention.

The Bolivian government has publicly stated its support for developing a legal global market for coca products, including coca-based tea, soft drinks and pharmaceuticals, which it argues would reduce demand for cocaine.