“No one living in China is more daring than the maverick writer Yu Jie,” journalist and historian Jonathan Mirsky wrote more than five years ago. It’s even more apt today.The 36-year-old Chinese dissident and writer is about to risk his freedom by publishing an explosive new title outing China’s cuddly premier, Wen Jiabao, as an authoritarian hard-liner behind the scenes.

In China’s Best Actor: Wen Jiabao,  Yu claims that “Grandpa Wen” has purposefully cultivated his populist image but in reality he is just as keen on restricting civil liberties as the rest of the party.

Chinese politicians are a distinct breed. Predominantly male, they are stiff and robotic on camera, fond of official speak, and sport identikit greased-back hairstyles.

Although 67-year-old Wen still has the hairdo, he comes across as the Communist Party’s first human being, their poster boy. He cries on camera. He hugs children on camera. He smiles and laughs on camera. He even shakes hands with Aids victims on camera.

But to Yu, this is all an act. There is little information yet as to what evidence Yu has for his accusations: That Wen is insincere and is not simply a victim of Communist party machinations, for example.

For that we will have to wait for the book to be published, which is August 16, according to Yu’s Hong Kong publisher, New Century Press. Yu is a best seller but all his books are banned on the mainland. Instead he publishes in Hong Kong, which still enjoys relative freedom of press.

It’s amazing that Yu has stayed out of jail so long. Over the years he’s spoken out for everything from religious freedoms to democracy. He once proposed that Mao’s body be removed from the mausoleum on Tiananmen Square. Most recently he’s spoken up for the exiled Tibetan leader, the Dalai Lama.

This is not the first book he’s published about the Chinese leadership either. Last year he released Confrontation between Liu Xiaobo and [President] Hu Jintao (Chinese name: ??????????) which went virtually unnoticed by the western press. Liu Xiaobo is another dissident writer currently serving 11 years for his efforts to call for political reform.

On his twitter, Yu, whose username is Yujie89 (a reference to the Tiananmen Square massacre) says his Wen book is much more risky because he is singling out the premier. Yu is going ahead with the book even though on Monday he was detained for four hours by police and threatened with jail if he published.

“As a writer, I consider freedom of speech an essential part of my life,” he told The New York Times. “Without it I will be a walking corpse, with no meaning and no value.”