Hong Kong CNN  — 

In a surprise decision Monday, a Hong Kong court threw out a month-old mask ban the government had introduced in the hopes of stemming the city’s ongoing political unrest.

But the ruling has provoked anger in China, with the country’s top legislature signaling that it may use this as an opportunity to drastically rewrite Hong Kong’s legal framework.

The original ban was introduced by the city’s embattled leader, Carrie Lam, using colonial-era emergency powers in the case of “public danger or emergency.”

On Monday, the court said that these powers, at least in the case of “public danger,” were unconstitutional and had been superseded by the city’s de facto constitution, the Basic Law.

That constitution was adopted following Hong Kong’s handover from Britain to China in 1997, and grants citizens in the semi-autonomous Chinese city freedoms that are unheard of on the mainland.

Following the court’s decision, the Hong Kong government said the controversial ban would no longer be enforced while it considered appealing. However, according to China’s top legislature, Hong Kong courts have no power to rule on the constitutionality of legislation under the city’s Basic Law.

“The constitution and the Basic Law together form the constitutional basis of the special administrative region,” a spokesman for the National People’s Congress, China’s rubber-stamp parliament, said Tuesday. “Whether a law … is in conformity with the Basic Law … can only be judged and decided by the NPC Standing Committee, and no other organ has the right to judge or decide.”

Were this rhetoric to be put into action, it could effectively end the right to judicial review in Hong Kong, a bedrock of the city’s rule of law. It’s also just the type of overreach from Beijing that has brought people out onto the streets for months.

While the NPC does have the constitutional right to “interpret” the Basic Law as a de facto supreme court, and has done several times in the past to great controversy, the assertion that lower courts cannot rule on constitutional matters is totally out of keeping with both the basic tenets of common law and Hong Kong jurisprudence.