A lawyer for Chinese dissident Liu Xiaobo says a Beijing court has rejected his appeal against an 11-year jail term handed down on Christmas Day for subversion.

Attorney Shang Baojun said the appeal had been turned down after a brief hearing Thursday morning. Liu was the co-author of a daring call for reform that was released in late 2008. Rights groups called his sentence a direct slap at international pressure, and a warning that treatment for dissidents will be increasingly harsh.

The vaguely worded charge of inciting to subvert state power is routinely used to jail dissidents in China. Liu could have been sentenced for up to 15 years, but rights groups said even the 11-year sentence was a shock.