The head of Beijing's liaison office yesterday declared "resolute opposition" to Occupy Central's threat of mass civil disobedience in pursuit of democracy.
Zhang Xiaoming said allowing a challenge to the city's laws would be a disaster and have long-term repercussions.
But Occupy organiser Benny Tai Yiu-ting hit back, saying Zhang did not understand the concept of civil disobedience.
"No matter how the organiser uses sweet words to whitewash the campaign, what is illegal remains illegal," Zhang said in response to questions after a lunch with lawmakers at the Legislative Council building.
"Hong Kong is a city with law and order," he said. "If it allows some people to challenge the law, it will be a disaster and there will be lasting consequences. It may be harmful to young people."
Zhang added that the Hong Kong government was experienced in handling political reform and he believed a consultation would be launched at the appropriate time.
Tai, an associate professor of law at the University of Hong Kong, said the campaign, which aims to bring Central to a standstill next July if the government has not presented a plan for true universal suffrage, would prompt a change to the political system and push to a fairer society.
He said Zhang lacked an understanding of civil disobedience, which was a way for people to rebel against what they deem to be injustice - in contrast to an illegal act, which in general meant an action to make personal gain. Tai has previously said that the blockade would be the movement's final step and a "last resort".
Zhang said yesterday's lunch was only a beginning and expressed the wish to have further communication with lawmakers.
"Unlike lawmakers, I am not used to debating in front of the media. I think a smaller scale of interaction would bear a better result."
In his speech, Zhang said the liaison office would like to organise study tours for legislators to visit the mainland to better understand the national conditions. "But do not say that it is brainwashing," he joked.
Labour Party lawmaker Lee Cheuk-yan and Civic Party leader Alan Leong Kah-kit welcomed further communication with the liaison office. But Lee said Beijing should give home return permits to pan-democrats banned from travelling to the mainland.