Xu Hong, director general of the Chinese foreign ministry’s treaty and law department, sought to clarify a colleague’s recent remarks suggesting the irrelevance of the treaty. He also assured Hong Kong that Beijing was committed to upholding the “one country, two systems” policy – not under the treaty, but because of a commitment in the city’s mini-constitution.

[…] “He said ‘it no longer has realistic meaning’. This is understandable when we look at the issue against the background that some country was trying to use the joint declaration for pointing fingers,” Xu said. “But we have never denied the fact that the joint declaration is a treaty.”

While acknowledging the document registered with the United Nations was “not without [legally] binding effect”, he pointed out that its main text only mentioned Britain would “restore” Hong Kong to China, but included no provision for its rights and responsibilities after the handover.

China’s basic Hong Kong policies, elaborated in annex I of the joint declaration, were a “unilateral” declaration over which Britain had no say, he added. [Source]

“Now Hong Kong has returned to the motherland’s embrace for 20 years, the Sino-British Joint Declaration, as a historical document, no longer has any practical significance, and it is not at all binding for the central government’s management over Hong Kong. The UK has no sovereignty, no power to rule and no power to supervise Hong Kong after the handover,” Lu said.

Britain said it had a legal responsibility to ensure China abided by its obligations under the declaration.

“The Sino-British Joint Declaration remains as valid today as it did when it was signed over 30 years ago,” a British Foreign Office spokeswoman said.

“It is a legally binding treaty, registered with the U.N. and continues to be in force. As a co-signatory, the UK government is committed to monitoring its implementation closely.” [Source]

At Lawfare, Julian Ku from Hofstra University School of Law argued that Lu’s statement did not translate into a complete voiding of the Joint Declaration in its entirety. Rather, only specific portions of the Declaration concerning the transition were considered no longer binding, with the confusion caused by subtle differences in translation between Reuters’ rendition of Lu’s statement and the official translation by the Ministry of Foreign Affairs.

[…In] reviewing the English translation of the spokesman’s remarks, we all might be overreacting a little. As always, the best understanding of what he really meant may require taking into account tricky problems of translation. Here is the MFA’s official translation of the same remarks translated by Reuters above:

It’s been 20 years now since Hong Kong’s return to the motherland, and the arrangements during the transitional period prescribed in the Sino-British Joint Declaration are now history and of no practical significance, nor are they binding on the Chinese central government’s administration of the Hong Kong SAR.

The key difference lies not so much in language as in grammar. In the Reuters translation, the phrase “not at all binding” refers to the “1984 Sino-British Joint Declaration.” But in the MFA translation, the phrase “nor are they binding” refers to the “arrangements during the transitional period prescribed in the Sino-British Joint Declaration” (emphasis added).  The difference is small but significant. In the Reuters version, China is saying the entire Joint Declaration is not binding, but in the MFA version, China is saying that the “arrangements during the transitional period” in the Joint Declaration are not binding. The English translation’s use of the plural “nor are they binding” makes this difference clear. Under the MFA translation, China could be saying those “arrangements during the transitional period” are not binding, but that the rest of the Joint Declaration (whatever that is) remains in force. [Source]

However, Donald Clarke at The China Collection responded that the original Chinese transcript itself suggested that the official translation was mistaken and that Lu was in fact referring to the Joint Declaration in its entirety.

1984年的《中英联合声明》就中方恢复对香港行使主权和过渡期有关安排作了清晰划分。现在香港已经回归祖国怀抱20年，《中英联合声明》作为一个历史文件，不具有任何现实意义，对中国中央政府对香港特区的管理也不具备任何约束力。

The Sino-British Joint Declaration of 1984 made a clear distinction between [a] China’s resumption of the exercise of sovereignty over Hong Kong and [b] relevant arrangements for the transitional period. It has already been 20 years now since Hong Kong returned to the embrace of the motherland; the Sino-British Joint Declaration, as a historical document, possesses no practical significance of any kind, and has no binding force of any kind with respect to the central government’s administration of the Hong Kong SAR.

We can see right away that the MFA translation is simply wrong. It is clear that the subject of the verbs in the phrases “possesses no practical significance” and “has no binding force” is the Joint Declaration in its entirety, not merely a subpart of it concerned with “arrangements for the transitional period”. Moreover, the context reinforces this point. In a statement about what is binding under the Joint Declaration and what is not, what could be the purpose of the first sentence stating that the Joint Declaration made a clear distinction between pre-handover transitional arrangements on the one hand and the post-handover exercise of sovereignty by China on the other? The answer seems unescapable: the MFA is saying that to the extent it was binding at all, the Joint Declaration was binding only with respect to pre-handover transitional arrangements. And (so the argument goes) as that transition period ended 20 years ago, there are of course no binding obligations left. [Source]