Hong Kong on Tuesday scrapped a plan to make coronavirus vaccines mandatory for foreign domestic workers after the proposal sparked an outcry and a diplomatic tussle.

But authorities ordered all foreign helpers to undergo another round of mandatory testing, triggering renewed criticism from the Philippines.

Health officials planned to roll out mandatory inoculations for the 370,000 domestic workers in the city, mostly poorly paid women from the Philippines and Indonesia.

Those wanting to apply for work visas -- or renew their current ones -- would need to show they had received two doses.

But on Tuesday city leader Carrie Lam announced a U-turn.

"The government has decided not to request mandatory vaccination when helpers renew their contracts," she said, adding the decision had been made after meetings with officials from the Philippines and Indonesia.

Philippine foreign affairs secretary Teodoro Locsin had previously said the initial proposal "smacked of discrimination".

Hong Kong health officials announced the mandatory vaccination plan and the testing of all domestic workers last month after two were found to be infected with one of the more virulent strains of the coronavirus.

They said domestic workers were "high risk" because they often work with the elderly and meet in parks on Sundays -- usually their one day off a week.

Labour groups representing domestic workers said they felt they were being singled out, noting that the families they worked for -- as well as locals working in environments such as care homes -- were not required to get vaccinated.

They also pointed out that wealthier foreign migrants such as the city's white-collar financial workers were not forced to get vaccines when outbreaks of the coronavirus were traced to their well-heeled districts.

Hong Kong's 370,000 foreign domestic workers are mostly poorly paid women from the Philippines and Indonesia
Hong Kong's 370,000 foreign domestic workers are mostly poorly paid women from the Philippines and Indonesia AFP / Philip FONG

The last round of compulsory testing saw long queues form at facilities across the city. Three coronavirus cases were uncovered over nine days.

On Tuesday, Lam said all non-vaccinated helpers would be ordered to undergo a second round of testing by the end of the month.

"We have to take precautions before any possible outbreaks, as we had found some infectious Covid-19 variants in the community," Lam said.

But that decision sparked fresh anger with a Philippines diplomat warning it would "not go down well with the community".

"I questioned the necessity of another mandatory test, citing the near-perfect compliance of domestic workers to the initial mandatory test," Consul General Raly Tejada told the South China Morning Post, describing recent meetings with Hong Kong officials.

Thanks to strict quarantine measures and economically painful social distancing rules, Hong Kong has kept infections to just under 12,000 cases and 210 deaths.

It has secured ample vaccine doses but the public take-up has been very low.

So far just 16 percent of the city's 7.5 million people have received one or more doses, a long way from the 60-70 percent considered necessary for herd immunity.

Regular polling shows Hong Kongers have some of the lowest support ratings for inoculation in the world.

Some of Hong Kong's BioNTech/Pfizer vaccines will pass their shelf life in September and officials fret they may be in the unenviable position of throwing away good doses.

The vaccination drive has been hampered by the government's public trust deficit.

After huge democracy protests exploded in 2019, Hong Kong's unpopular unelected leaders -- with the backing of Beijing -- have overseen a sweeping crackdown on dissent in the city.