"The focus for the month of September will be strengthening economic propaganda and . . . promoting the discourse on China's bright economic future and the superiority of China's system," the party's propaganda department said in a directive to national media outlets.

That "bright future" is a picture that has been clouded by bleak economic data points and plunging shares in recent months. Turmoil in China, exacerbated by last month's currency devaluation, unleashed a global stock market rout.

A photograph of the latest directive was posted online by California-based China Digital Times, which monitors Chinese media and internet censorship. "They want to control how the media frames and interprets [economic data], making sure that they all focus on positive things," said Xiao Qiang, CDT founder.

CDT also posted a notice from the chief editor's office at the Xinhua news agency, dated September 7, that reiterated the need to "stabilise expectations and inspire confidence". The Xinhua notice instructed staff to "please plan related reporting" and send their story ideas to the agency's Creative Planning Center.

Chinese journalists who do not follow party instructions can face severe punishment. Late last month, a reporter for one of the country's leading financial magazines was detained by police and allegedly confessed to causing "panic and disorder" on the stock markets in July.