Benny Tai, one of the three founders of the Occupy Central with Love and Peace movement, said the movement has now run its course and warned that protesters now risk further violent clashes with police if they stay in their camps.
"Occupation is now a high-risk, low-return business," he said in an editorial in the New York Times, arguing that campaigners should instead turn to "acts of noncooperation" such as refusing to pay taxes.
Campaigners have camped out on Hong Kong's streets for more than two months to demand fully free elections for the southern Chinese city's leadership.
The rallies drew tens of thousands at their height, but numbers have dwindled as public support for the movement has waned and dozens have been injured in clashes with police as authorities have tried to clear the camps.
So far one of three camps established by the movement has been dismantled, and Hong Kong authorities are gearing up for more clearances next week.
Around 100 academics, with some in full ceremonial gowns, held a rally in support of students and marched towards the Admiralty protest site today, where they were greeted with applause.
Some scholars held signs saying "I want true universal suffrage" and held yellow umbrellas, a symbol of the democracy movement.
"They are our students and they are pursuing something that is not just for themselves but is for the whole society," Esther Ho, professor of educational policy and administration at the Chinese University of Hong Kong, told AFP.
Student protest leaders have until now remained adamant that staying on the streets is their only option to force reform.
