Hong Kong’s embattled leader has shrugged off claims that the unpopularity of her administration is an impediment to the city’s mass testing scheme for Covid-19, hitting back at a union formed by public health workers calling for a boycott. “I don’t think it has something to do with the government’s popularity,” Chief Executive Carrie Lam Cheng Yuet-ngor said on Tuesday during her weekly press briefing, before pointing the finger back at “people” who lacked understanding of the scheme and tried to cause “worries and fears”. Lam was referring to the Hospital Authority Employees Alliance (HAEA), an opposition union formed by frontline staff at public hospitals amid last year’s anti-government protests, which joined prominent activist Joshua Wong Chi-fung to call for boycott of the citywide testing days ago. Calling the test “safe, simple, convenient and quick”, Lam urged the group to view the scheme through an “objective and unbiased” lens, appealing to the public to get tested for “themselves and their loved ones”. The city on Tuesday launched its voluntary mass testing scheme for more than 7 million people, aimed at tracking down invisible transmission chains in the city amid a fierce but dwindling third wave of coronavirus infections. The scheme is intended to last for a week, but may be extended by another if needed. Asymptomatic patients have accounted for a quarter of the city’s 4,822 infections, as of Tuesday. Hong Kong has so far recorded 90 deaths linked to Covid-19, with the most recent cases coming from clusters in elderly homes. Amid its deeply divided political landscape, public health issues have also been caught in the crossfire. Mainland China has sent support teams at Lam’s request to set up makeshift laboratories to boost the capacity of the mass testing programme. But soon after registration began on Sunday, the HAEA held a press conference with activist Wong, to question the safety and effectiveness of the programme. Beijing’s Hong Kong and Macau Affairs Office and its liaison office in the city have lashed out at critics questioning pandemic help provided by mainland authorities, calling them “evil” for slandering the cooperation. Lam also took the initiative to dismiss the alliance’s claims on Tuesday, saying that errors were bound to happen in any sort of scientific testing. “All the preliminary results from laboratories, including those from the Hospital Authority, will be reviewed by the Centre for Health Protection,” Lam said, calling the process rigorous. While the alliance argued that a mass testing scheme would not work without a full lockdown, Lam said it was impossible for Hong Kong to implement one, as a degree of freedom had to be maintained for the public. Dismissing the alliance’s warning that people could be infected as they queued for tests, Lam said various medical professionals had explained how the risk of cross-transmission had been reduced to a minimum at testing centres, while location choices had also factored in the need to avoid impacts on local communities. The alliance also cited the World Health Organisation’s advice on targeted testing. Lam agreed, but said the present situation allowed the city to offer more. “With the resources from the central government, we can do this one-off,” she said. ‘The Covid-19 test made me cry’: what it’s like under Hong Kong’s mass screening scheme Lam was also asked why schools could resume in September, when the Legislative Council elections , initially slated for September 6, had been postponed for a year over virus concerns and could not take place sooner. The chief executive said organising the polls was far more complex, as it involved time set aside for electioneering. She also said Legco worked in cycles. She had previously said she did not want the postponement of the elections to affect Legco matters, such as the scrutinising and approval of the government’s budget from February to May each year.