A Chinese court has jailed a writer for 10 years on subversion charges for writing essays that urged people to defend their rights, a relative said, the third person to receive a lengthy jail sentence on such charges in less than a month.

The sentences suggest a crackdown on dissidents is intensifying ahead of the anniversary of online calls for the Arab-inspired Jasmine Revolution rallies and before a leadership transition later in the year.

The court in Wuhan in central China tried Li Tie in April last year but only declared him guilty on Tuesday of subversion of state power, the relative, who declined to be named for fear of retribution, told Reuters by telephone.

The charge is more serious than the one of incitement, often used against critics of the ruling Communist Party.

He said in court: 'I'm not guilty. When have I subverted state power?' the relative said.

The state has made this conclusion against him, the relative said. You can't understand it. Under these circumstances, you're helpless. But this is our reality. He sat in front of the computer subverting state power.'

Calls to the Wuhan Intermediate People's court about Li's case were unanswered.

Li, 52, was convicted for writing 13 essays that called for defending people's rights that he published in newspapers overseas and on the Internet, said the relative. One of the essays was entitled Human Beings' Dignity is equivalent to heaven, the source said.

He worshipped Chairman Mao and would use Mao Zedong's Thought in his essays, the source said, referring to the communist theory espoused by China's former paramount leader. He always used to tell me: 'I'm using the language of the Communist Party, so why are they after me?' the relative said.

The sentence was handed down in half an hour, he added, noting the court would not allow Li's lawyer to represent him and appointed another lawyer to do so. Li was allowed to meet only with his mother and daughter.

Li was initially detained by the Wuhan public security bureau in September on suspicion of inciting subversion of state power, the relative said.

When the Wuhan court issued a formal notice on Li's arrest a month later, the charge had been changed to subversion of state power, he said. The relative said the court did not give a reason for the more serious charge.

Li was a member of the China Social Democracy Party, according to the Chinese Human Rights Defenders. China typically invokes subversion if there is an existence of some underground organisation, said Nicholas Bequelin, a researcher with Human Rights Watch.

Defendants facing subversion charges in China's party-run courts are almost never acquitted.

CRACKDOWN

Communist Party chiefs are preparing for a leadership handover late next year, when the party's long-standing focus on fending off political challenges is likely to intensify.

We are not optimistic that the new leadership will be any different than the current leadership in terms of human rights, Sarah Schafer, East Asia Researcher for Amnesty International, said in emailed comments. But we can hope that just maybe they'll be brave enough to change this repressive environment and welcome different voices rather than stifling them.

The latest sentence comes barely a month after two dissidents were given harsh sentences for inciting subversion in December. One was jailed for ten years, the other was given a nine-year sentence.

All these elements make me think this pattern indicates that it's a decision that follows directions given at the highest level, said Bequelin.

There's a premium on snipping in the bud anything that the party considers a threat to social stability, monopoly on power and the party, he said. There's been a considerable shift in human rights diplomacy under (President) Hu Jintao with China being more assertive and pushing back more aggressively on international pressure on human rights.

China's broad crackdown on dissent stems from a mix of arrogance and insecurity in Beijing, Yu Jie, the most recently exiled Chinese dissident, said in Washington on Wednesday.

During the past decade, Li has written many online articles promoting democracy, constitutional government, and direct local elections, according to the Chinese Human Rights Defenders.

Chinese authorities indicted veteran dissident Zhu Yufu on subversion charges for writing a poem urging people to gather to defend their freedoms, his lawyer said on Tuesday.

What the activists have in common is their long-term unwavering commitment to democracy, said Songlian Wang, research coordinator for the rights group.

By doling out harsh sentences against them, the Chinese government is sending a clear message in response to the Arab Spring. It is drawing a red line: advocate democratization and you'll be given a decade in prison.

(Additional reporting by Michael Martina; Editing by Ken Wills and Nick Macfie)