One former classmate, Wu Zongmin, who is now a mathematics professor at Fudan, told the : "His only prospect in life was to learn mathematics and continue his career as a secondary school teacher after graduation."

Those who know Li say his humble, flexible and easy-going manner was already well established during that modest period of his life. Analysts believe such characteristics will serve him well if Li, as widely expected, is tipped to become vice-president in charge of Hong Kong and Macau affairs.

Friends, classmates and colleagues describe him as a reform-minded leader open to new ideas and initiatives, provided they meet a careful cost-benefit analysis. That could possibly include controversial political reform proposals on the mainland and in Hong Kong.

A former subordinate of Li's said: "He is flexible in policy and thus he would adopt a more tolerant approach in regard to Hong Kong affairs as it is under the one-country, two-system formula. However, he is not radical. While he is bold in accepting new things, he is also cautious in trying experiments."

Li was born in 1950 in Liangshui, Jiangsu province. He father, Li Gancheng , was a vice-mayor of Shanghai in the 1960s, making him a member of the Communist Party elite.

But that status, which today makes Li a "princeling", did little to protect him in Mao Zedong's purges during the Cultural Revolution. Like many of the children of revolutionaries, he was "sent down" to the country to work as a labourer.

He was among the first wave of students to enrol in universities when entrance exams resumed in the first two years after Mao's death in 1976, the so-called 77th and 78th classes. Those students now make up much of the country's ruling elite, and hold several seats in the party's powerful Politburo.

Chen Zhimin, a professor at Fudan's School of International Relations and Public Affairs, said: "The 77th and 78th students have played major roles in sowing new thinking, reforming the old system and guarding the new in the past three decades."

At university, Li established a reputation for being both accommodating and assertive. His classmate Wu recalled how Li accepted a less desirable bed near a door so that a classmate could have a better one near a window.

Another time, Li, acting as student representative, asked Su to push back the dormitory's scheduled lights-out time to 11pm from 10.30pm so students could continue reading without having to go into the lobby.

Although he joined the party in 1978, Li did not seem to pay much mind to politics. Many expected him to pursue a career in academia, like large numbers of his classmates, who are now scattered across the prestigeous universities of the world, from Chinese University of Hong Kong to Harvard.

"Like most students of sciences, who are usually indifferent to politics, Li showed no particular interest in controversial political issues at that time," the former colleague said.

His shift towards politics came after graduation, when Li became an assistant professor at Fudan's School of Management and agreed to serve as the school's secretary for the Communist Youth League.

In 1983, an early patron of Li's, Shanghai party chief Chen Pixian, recommended the young professor to then general secretary Hu Yaobang to serve as Youth League secretary for the entire university.

It was a major break. The Youth League was becoming a key power base for future president Hu Jintao and Li rose quickly through the ranks of what is now known as the or the "Youth League faction" of the party.

By the end of his first year as a full-time league leader, Li had become secretary of the Shanghai league. He later moved up to the same post in Beijing, where colleagues remember him as intelligent and personable, with a ready smile.

"He is poised, but without an official air," a former colleague said under the condition of anonymity. "He is cautious, but not indecisive; he is flexible, but not unprincipled; and he is pragmatic, but not without ideals."

Li was later appointed to the top party posts in Nanjing and Jiangsu before being promoted to the Politburo and placed in charge of the Central Committee's Organisation Department in 2007. In that powerful role, he oversaw the personnel assignments for the entire 80-million-member party.

In the meantime, he attended Peking University and the Central Party School, earning bachelor's, master's and doctoral degrees. In 2002, he completed a five-week training programme at Harvard University's Kennedy School of Government.

With such a background, Li is often seen as an exemplar of the new generation of party leaders: well educated, with a good administrative track record and exposure to the outside world.

Steve Tsang, who heads the University of Nottingham's China Policy Institute, said: "While all the third and fourth-generation leaders received an education in Soviet-style planned economics, the new leaders are generally younger, better educated and, to some degree, less ideological, as many received an education increasingly influenced by Western ideas in economics, law and politics."

Because of his background and ties to Hu Jintao, many expected that Li would ascend to the Politburo's supreme Standing Committee after the 18th party congress earlier this month. That did not come to pass, if only because the Standing Committee was reduced to seven members.

Analysts say he remains a figure to watch and, at 62, is young enough to be promoted after the next party congress in 2017.