The government’s refusal to impose a full shutdown, in part to protect the flow of goods and vital supplies, was also called a “complete con” by a senior figure in the city’s logistics industry.

Latest infection figures for coronavirus in Hong Kong

But the government has stuck to its strategy of drastically reducing rather than stopping the cross-border flow of people, as well as mitigation measures such as closing schools for more than a month, and advising people to work from home.

Among those closed were major land and sea crossings including the Lo Wu and Lok Ma Chau checkpoints, and the Hong Kong-Macau Ferry Terminal, which together accounted for about 60 per cent of cross-border passenger traffic in 2018.

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But more than 111,000 Hongkongers and over 13,400 mainland visitors still arrived in the city on Tuesday.

Sunny Ho, executive director of the Hong Kong Shippers’ Council, the logistics trade body, challenged Lam’s argument that some crossings needed to stay open to enable a steady supply of goods and daily necessities.

“This is a complete con by the government, as goods still enjoy unfettered access across the checkpoints. Only the movement of people was restricted under the new policy. So rest assured, food and key supplies won’t run out,” Ho said.

A government source maintained it would be difficult to handle the flow of goods if all borders were closed, especially with the system of health checks.

“Should we ask the driver to leave the trucks at the border and ask another driver from Hong Kong to send the goods to the city instead?” the source said.

But Ho said many cross-border truck drivers were Hong Kong residents holding local driving licences to operate on the city’s roads, and added that temperature screening was already being conducted on a daily basis on the drivers. Similar and maybe more stringent checks could be imposed on drivers.

Hung Wing-tat, a fellow of the Hong Kong Society of Transportation Studies, said the partial border shutdown was already as far the as government could go to reduce human traffic.

“There is now only one land crossing to each of the major neighbouring cities, the Hong Kong-Zhuhai-Macau Bridge to Zhuhai and Macau, and the Shenzhen Bay Port to Shenzhen,” he said.

“The government has probably buckled under lobbying pressure so businesspeople can still cross the border.”

Its Chief Executive Ho Iat-seng said that would deprive the city of it vital workforce, such as cleaners, who live in the mainland, as well as essential supplies.

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Paul Yip Siu-fai, chair professor in social work and social administration at the University of Hong Kong, said labour shortages would not happen in Hong Kong, because the city did not rely on imported labour in the cleaning industry.

He said the “half-hearted” measure currently in place actually made matters worse.

“More people will now squeeze into the remaining crossings, which will result in queues and crowded environments conducive to the spread of the virus,” he said.

He echoed remarks by Gabriel Leung, dean of HKU’s faculty of medicine dean, on Tuesday calling for more decisive and timely action, and said a mandatory 14-day quarantine should be imposed on all travellers crossing the border including Hongkongers, which would be effective in further restricting the flow of people.

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But apart from the headache of fending off the pressure from businesspeople or workers, or even cross-border families who need the checkpoints to stay open, there could be a much bigger worry that explains the reluctance of Lam’s government to act: the lack of capacity to deal with the need to track, isolate or quarantine such frequent travellers.

A source close to the government admitted it would be impossible for the administration to cope with all Hongkongers returning from the mainland: “Where can we quarantine them? Do we have enough manpower to operate the quarantine sites?”

While most residents have been vocal about not having such sites close to their neighbourhoods, political parties have not been short on suggestions.

It is a call being echoed by others.

“Desperate times call for desperate measures,” social work professor Yip said. “If we even need to put Hongkongers in quarantine camps in mainland China for 14 days, before those without symptoms could return, then so be it.”

The proposal, however, will gain no traction with a government already not in the good books of Beijing, said others. The dithering by the government might have come from a lack of capacity and resources, but also fear of lack of political backing.

At the heart of Lam’s dilemma was a political problem, said Lau Siu-kai, vice-chairman of the semi-official Chinese Association of Hong Kong and Macau Studies.

“Carrie Lam already does not have a lot of political capital to dispense with, after her debacle in handling the prolonged civil unrest,” Lau said. “Bear in mind, she has already asked Beijing for a lot of favours, such as the suspension of individual travel visas for mainlanders to come to Hong Kong.

“Crucially, Lam still has to rely on Beijing for her own political survival and ongoing cooperation from the mainland authorities on information sharing and resources to defeat the epidemic.”

The veteran political commentator said the opposition camp and the medical sector’s actions might have backfired though.

“It’s kind of pushed her into a corner, where she risks humiliation if she backs down,” he said. “Right now she doesn’t have many options left, that’s why she has been dragged kicking and screaming, and only announced limited border closures and other measures bit by bit.”