The Basic Law of the Hong Kong Special Administrative Region has guaranteed the smooth implementation of "one country, two systems" since 1997, and contributed to the city's stability and prosperity, as well as its people's well-being, political heavyweights said on Friday.

Their remarks came a day ahead of the 30th anniversary of the constitutional document, which was promulgated on April 4, 1990, after five years of drafting and extensive consultations and discussions involving various sectors of the local community.

Tam Yiu-chung, a former member of the Hong Kong Basic Law Drafting Committee, recalled that the political environment at the time was quite different from today's, with the Chinese mainland's reform and opening-up in its incipient period and members of the drafting committee lacking the experience with such an innovative political system.

"However, everyone was passionate about the 'one country, two systems' principle and believed it will succeed," said Tam, who is now Hong Kong's sole member of the National People's Congress Standing Committee.

The ensuing decades, he said, have proved that "one country, two systems" could be turned into reality. The institution had resulted in the smooth transition and transfer of Hong Kong when it returned to the motherland in 1997, and also helped maintain Hong Kong's stability and prosperity in tough times, such as the global financial crises in 2008.

Tam said the central government has shown its respect and sincerity from the drafting of the Basic Law till today, and exhibited persistingfaith in in upholding "one country, two systems" without distorting it.

The Hong Kong community should have a solid understanding of the Basic Law and the "one country two systems" principle, said Tam. Some people should stop talking about only "two systems" without mentioning "one country", or talking just about their rights as stipulated in the Basic Law, but ignoring the obligations, he added.

David Wong Yau-kar, a Hong Kong NPC deputy, said the Basic Law has been the cornerstone of the city's stability and prosperity in recent decades as it provides the legal basis for implementing "one country, two systems".

Looking ahead, he said the SAR government should further promote Basic Law education in the community in future, and it's necessary to strictly enforce the law to bring those violating the Basic Law to justice.

Hong Kong will not have a bright future without the guidance and constraints under the Basic Law, he said.

Stanley Ng Chau-pei, president of the Hong Kong Federation of Trade Unions, said Hong Kong people have enjoyed an unprecedented array of rights and improved their livelihood following the city's return to the motherland, thanks to the emphasis on,and protection of people's rights in the Basic Law.

He noted that the Basic Law has guaranteed workers' rights and interests on a legal basis, such as ensuring their rights to establish trade unions and basic salaries. In the past decades, the activities of trade unions and other grassroots organizations have been safeguarded by the guiding provisions in the Basic Law.

Tian Feilong, a member of the Chinese Association of Hong Kong and Macao Studies, said the Basic Law ensured that Hong Kong continues its own economic system after the handover, and the SAR has helped boost the mainland's economic development in the past 23 years.