The law is simply plugging a loophole, they claimed, and is no different to what many other countries have on the books. Local officials and prominent businesses threw their weight behind the bill -- sight unseen -- promising that it would leave the city better off, and in any case, would only affect a handful of people.
On Saturday, China's National People's Congress (NPC), which is expected to pass the law in coming weeks, gave Hong Kong its first glimpse of what it contains. The critics may have been right to be worried: as drafted, the law appears to upend the city's prized independent legal system, allowing Beijing to override local laws while enhancing its ability to suppress political opposition.
Most controversially, the law gives Beijing the power to exercise jurisdiction over select criminal cases, raising the prospect that for the first time in Hong Kong's history, suspects could be extradited across the border to face trial, and potentially prison time, in the mainland.
Fears of just that were what drove protests against an extradition bill last year that was proposed by the Hong Kong government. Those protests eventually forced the abandonment of that law, but spiraled into broader anti-government unrest that, Beijing says, required the imposition of the new national security regulations.
Antony Dapiran, a lawyer and political analyst based in Hong Kong, described the new law as a "broad-based power grab by Beijing" over many of the key elements of government and society.
Writing on Twitter, he said the new law "effectively sets up a parallel judiciary (and) takes interpretation and final adjudication power away from Hong Kong courts."
In a statement, the city's chief executive, Carrie Lam, said the law would ensure "the long-term prosperity and stability of Hong Kong," reiterated that it would "only target an extremely small minority of people" and said the proposed bill was "in line with the rule of law" and the "rights and freedoms which are applicable in Hong Kong under the Basic Law and relevant international covenants."
When Hong Kong was handed over from British to Chinese rule in 1997, the city's common law system remained largely intact. Precedent remained in force, and protections under the new de facto constitution, Basic Law, as well as various international treaties, guaranteed a degree of fairness and freedom not seen in China, where the conviction rate is north of 90%.
While the NPC did gain the ability to "interpret" Basic Law, essentially rewriting it in certain cases, the central government did not have any jurisdiction over individual cases, nor could people be tried for crimes against Beijing that were not illegal in Hong Kong.
The new national security law would change all of that. According to details published over the weekend, Chinese security organs will have the power to "exercise jurisdiction" over national security cases "under specific circumstances," while other prosecutions under the law will be heard by a panel of judges picked by the city's Beijing-appointed leader.
It does not say explicitly whether suspects could face extradition to mainland China under such circumstances.
Though the draft did make reference to upholding the "rule of law" and various civil liberties, it also subordinates existing law to the national security bill, so that where there is a conflict, the national security law prevails. In practice, this could mean that when a national security prosecution contravenes human rights protected under Hong Kong law, those rights are suspended.
Writing after the Saturday announcement, Jerome Cohen, an expert on Chinese law, dismissed the "eye candy" on human rights, pointing out that the "very provisions in the draft (law) would appear to violate those protections."
"The Handover has clearly become the Takeover," Cohen added.
Kevin Yam, a Hong Kong-based solicitor and former convenor of the Progressive Lawyers Group, said the proposed law was not worth legal interpretation, adding "there's nothing to analyze."
"It's just whatever they say it is," he added. "And if they cannot make it whatever they say it is when they want something, they will just change it in whatever way they like."
While there has been no suggestion of a true public consultation or referendum on the bill, multiple provisions revealed Saturday appeared geared towards allaying Hong Kongers' fears over it, or at least easing its selling to the public.
Such provisions come amid a massive propaganda effort to sell the bill, with posters and adverts promoting it plastering Hong Kong, as well as an apparent push by Beijing for Chinese firms to re-list on the city's stock exchange, boosting the local economy.
In particular, the creation of a panel, nominated by Chief Executive Carrie Lam, to hear national security cases, may have been a sop to those who were expressing alarm at reports the bill would bar foreign-born judges from hearing them. As part of the wider common law system, which also includes the UK, Canada, Australia and a number of other jurisdictions, Hong Kong periodically appoints distinguished "non-permanent" judges to the Court of Final Appeal.
These judges are appointed by the chief executive, but their presence in certain cases has been controversial in China, leading to calls for their removal, or barring them from certain sensitive cases. By giving Lam the power to nominate judges to hear national security cases, the government essentially sidesteps this issue, enabling her to choose those judges deemed most loyal.
The Hong Kong Bar Association has blasted the plans as "extraordinary" and a major blow to judicial independence, pointing out that Lam will be appointing a panel to oversee cases in which she herself is an interested party.
Speaking to local media, Bar Association head Philip Dykes said the law was a "recipe for conflict of interest," and would allow Lam to "cherry-pick" which judges heard the most controversial cases.
Alvin Yeung, an opposition lawmaker and barrister, said the proposal was a "clear departure from common law traditions."
Expanding the power of Chinese courts and security services to Hong Kong carries with it even more concerns.
Permitting China's security apparatus to operate in the city raises the specter of extralegal persecution. Dissidents and activists in China are often disappeared by the authorities or threatened with arrest around sensitive events, and many journalists and lawyers are dragged in to "take tea" with the security services, during which they receive thinly-veiled threats about the potential consequences of their work.
Giving Chinese courts jurisdiction "under specific circumstances," meanwhile, will likely guarantee convictions in those cases. China's legal system has been widely criticized for its lack of human rights protections, nakedly political prosecutions, and a nearly universal conviction rate. The country's own national security law has been interpreted broadly in the past to imprison activists, intellectuals and journalists.
Two Canadians prosecuted last week for spying are a pertinent example of this. Michael Kovrig and Michael Spavor were arrested in late 2018 shortly after the detention in Canada of Huawei executive Meng Wanzhou. While China argues there is "solid" evidence against the two men, Canada views the case as "arbitrary" and politically-motivated.
Kovrig and Spavor are also an example of how national security legislation in China differs to that in democratic countries. Canada, for example, has laws against espionage and spying, and people have been prosecuted under them.
The difference is that those laws and the corresponding prosecutions must conform to the Canadian Charter of Rights and Freedoms, the country's bill of rights, and could be struck down were they found by a court to be unconstitutional.
This is not the case in China, and may soon not be the case in Hong Kong, if the proposal for the law goes ahead. While China does mention certain rights in its constitution, these are subordinate to the law, not overriding. Freedom of expression, religion and the press exist in principle, but "may not infringe upon the interests of the State."
Similarly, Hong Kong guarantees rights under Basic Law and through being a signatory to international conventions, but the national security law as drafted would override these protections.
Those who attempt to assert their constitutionally-protected rights in China are often prosecuted on the grounds of national security, such as Nobel Peace Prize laureate Liu Xiaobo, who died in 2017 after years in prison on charges of "inciting subversion of state power." Liu's most famous work, Charter 08, of which he was a co-author, called in part for judges to be able to "uphold the authority of the Constitution."