Leong took issue with Lam’s remarks that while some people believe that the central or local governments should promise to improve the electoral model, “the ultimate goal” – which a Basic Law article states is universal suffrage – “is achieved if the chief executive were elected by ‘one man, one vote’”.

“Lam … with her very carefully chosen words, has said it all,” Leong said.

“She said once we passed any model that is restricted by [Beijing’s framework issued on August 31 last year], that would be the ultimate model envisaged by the Basic Law’s Article 45,” he said.

Pan-democrats would launch a counter-campaign to the government’s publicity drive to promote the reform package, Democratic Party lawmaker Helena Wong Pik-wan said.

They are starting this Sunday near Wan Chai MTR station, and thereafter every weekend in different neighbourhoods. They will distribute leaflets to explain to the public why they will veto the proposal in Legco, and how the scheme falls short of democratic expectations.

Joshua Wong Chi-fung, convenor of student group Scholarism, said the group would protest when government officials promoted the reform package in the coming weeks.

READ MORE: The road to universal suffrage: A timeline of Hong Kong’s journey to votes for all

“There could be a large-scale occupation if some pan-democrats change their mind and vote in support of the package,” Wong said. ”But I am not sure whether Scholarism will take the lead.”

He described the reform package as “retrogressive”, especially the arrangement that the public vote would run for only one round with the “first-past-the-vote” system.

“Imagine 90 per cent of the votes cast are a blank vote [in protest of the system], and the winner gets only 5 per cent of the popular vote,” he said. ”This could lead to a society that’s even more torn apart and there could be a governance crisis.”

Earlier, the chief secretary said the Basic Law, Hong Kong’s mini-constitution, “provided the legal foundation” for future amendments to the model, but “it will be up to the chief executive, based on actual situations, to decide whether an amendment is needed”.

She said she believed the next chief executive would have much more “political power” to consider further improving the political system if he or she was returned by universal suffrage.

However, Lam cautioned that even if the next administration could again launch the five-step process to seek political reform, there is no guarantee that the National People’s Congress Standing Committee, China’s top legislative body, would revise its decision.

Responding to a question by Ip Kwok-him of the pro-Beijing DAB party, Lam said: “The pan-democrats should ask themselves: Even if the next chief executive would start the five-step process again, how can they guarantee that the NPC standing committee would come up with another decision?

“Or how can they be sure that another decision would come up with something that is closer to the system they wish?”

Pan-democrats have slammed Beijing for “backtracking” on its promise in the 1984 Sino-British Joint Declaration that Hong Kong shall enjoy a “high degree of autonomy”.

Labour Party lawmaker Cyd Ho Sau-lan said her party would reject the reform package because they saw it as Beijing’s way of “testing Hongkongers” on their resolve to achieve democracy.

Before the Legco meeting, hundreds of protesters both for and against the reform package gathered at the designated demonstration area.

Members of the Federation of Trade Unions waved Chinese national flags, while People Power supporters held up yellow umbrellas, the symbol of the pro-democracy movement. Rival groups tried to drown out each other’s voices with loud chants and scuffles ensued when protesters barged into each other’s camps.

The demonstration continued as People Power lawmaker Albert Chan Wai-yip trailed Lam as she walked into the Legco chamber.

Chan, holding a yellow umbrella, shouted, “Down with the Hong Kong communist regime! Civic nomination is indispensable!”

Meanwhile, the Progressive Lawyers Group, formed by more than 60 mid-career barristers and solicitors, said today that they were “disappointed” at the reform blueprint.

Lam had announced a low threshold of 120 votes for a candidate to enter the 2017 race – but the lawyers’ group blasted it as merely a “smokescreen” as a candidate would ultimately require support from more than half of the 1,200 nominating committee members.

“The group is disappointed by the disrespect paid by those in power to the rule of law in twisting clear legal and constitutional concepts for their own ulterior political ends,” the group said.

The group demanded that the proposal be rejected and withdrawn, and that the government should act swiftly to present a new proposal that complies with domestic and international law.

In her speech, however, Lam staunchly ruled out any room for amendments in the package to appease the pan-democrats.

“We do not see any need to make further announcements,” said Lam, “It has been clear that there are legal ways to initiate changes [to the political system].”

The State Council’s Hong Kong and Macau Affairs Office welcomed the reform proposal as “legal, feasible, rational and pragmatic”.

In a statement issued this morning, the office’s spokesman said the proposal had taken care of the different sectors’ interests and demands as he called on Hongkongers to reach a consensus in implementing universal suffrage by 2017.

Separately, Scholarism donated HK$200,000 to the de facto referendum campaign of Democrat Albert Ho Chun-yan.

Ho will resign from his Legco seat after casting his vote on the reform package to trigger what pan-democrats are billing a citywide poll on democracy.

The group will meet tonight to decide whether it would join the decision-making group for the campaign and whether it would help raise more money for the cause, its convenor Wong said. Pan-democrats have estimated that seven parties, including Scholarism, should each raise HK$800,000.

Tony Cheung, Ng Kang-chung, Joyce Ng, Jeffie Lam