Dismissed from Peking University, outspoken professor Xia Yeliang's 13 year tenure at China's most prestigious educational institution ended without fanfare, surrounded by a handful of students in a tiny, out-of-the-way fifth-floor classroom.

After his final three-hour economics class had drawn to a close, the 53-year-old Xia, one of the original signatories of the pro-reform petition Charter 08, said a few quiet goodbyes on Thursday evening.

Xia maintains he was forced out of his job due to his persistent calls for political change in China, a charge university officials deny, and had no plans for a formal gathering with supporters that night, or perhaps ever.

His future abroad -- he says he has been offered visiting research fellowships in the US by Wellesley College, Harvard University and an unnamed think tank -- could depend on it.

"A lot of people have been wanting to get together, but I've been keeping a low profile so as not to offend the government," Xia told AFP. "Because if I truly provoke them, they won't let me leave. I'm worried they'll grab me at the airport."

Charter 08's main author, Liu Xiaobo, has since been sentenced to 11 years in prison by Chinese authorities and awarded the Nobel Peace Prize.

Xia himself has been an outspoken critic of the ruling Communist Party for years, but has said he may have been expelled from his post because of his more recent call for Chinese intellectuals to publicly debate political reform.

Following warnings from university officials, an economics faculty panel voted in October not to renew Xia's contract at the end of the autumn term, citing student evaluations that ranked him the lowest among the school's teaching staff.

The move set off an international furore, drawing condemnation from professors overseas arguing that nothing less than academic freedom -- already limited in China -- was at stake.

On the other side were several of Xia's former students, who in interviews and open letters criticised his teaching style and voiced support for his expulsion. Then the university itself redoubled its efforts by posting a lengthy defence of its decision online.

As he finished his last class, Xia maintained that the university was "not telling the truth", arguing that officials' explanations had changed over time and that not one of his thousands of former students had personally complained to him.

"I've been teaching at Peking University for more than a decade. No student has ever told me I'm a terrible teacher," he said, adding: "I don't believe I'm the worst professor in all of Peking University in all of history."

No Chinese university has offered him a position and he has already bought a plane ticket to the US, although the recent cases of several other outspoken government critics make him uncertain whether he will be allowed to leave.

Xia ticked off the names of detainees: Chinese-American investor and social media celebrity Charles Xue, billionaire activist Wang Gongquan, and Xu Zhiyong, a prominent activist and human rights lawyer.

"And then me and this situation," Xia said, noting that two other outspoken academics -- Chen Hongguo at the Northwest University of Politics and Law in Xi'an and Zou Hengfu, a Peking University professor who faces a lawsuit for claiming university officials sexually harassed waitresses on campus -- have in recent weeks had their overseas travel curtailed.

"The goal is that they don't want dissidents to criticise the government," Xia said. "And they also want to intimidate intellectuals, so that none of them will dare to speak out again."

Despite losing his job, Xia said that he believes that one day he may be able to return to Peking University, where he had once imagined himself teaching until his retirement.

He called his departure "a shame" and described his feelings on his last day of class as "yiyouweijin," a Chinese phrase meaning "to have not fully expressed oneself". And he voiced words of support for the university itself.

"In spirit, I will always be connected with Peking University," Xia said. "I deserve to be called a true Beidaren (Peking University person). Because in Peking University's spirit, there's an aspect of all-embracing freedom of thought. I achieved it. I'm a true Beidaren."

Whether the institution itself agrees is another matter: by Friday morning, the day after his last class, Xia's profile had already been removed from the university's website.