Charles Cheng, a university lecturer in humanities, struggled for months over whether he should leave his well-paid, good status job in Hong Kong for an uncertain career path in Taiwan, but he felt he could no longer honour his values and principles by staying.

“The government is spreading its influence in every area,” he said. “Starting 2022 I would have to teach one course related to national security.”

While some colleagues felt they could work within the government’s guidelines, he knew he could not.

In my position, I’m supposed to “talk about how we should have hopes and desires to change society. Now, I don’t think we can change society. So how can I teach the coming generations?” he asked.

Other university colleagues were also leaving to keep their freedom of speech and to protect their children from a politicised environment, he said.

“Hong Kong education is like brainwashing. Some of my other friends are working as teachers in primary or secondary schools and they want to leave because of their concerns for their kids.”

The impact of the mass exit is already reshaping society.

A December poll by the Hong Kong Association of the Heads of Secondary Schools found that local schools lost almost 4,500 students and 1,000 teachers in the last academic year amid a broader emigration wave.

“It is very clear that people still don’t trust the government and there is a whole lot of uncertainty in society,” said Mr Lau.

But the decision to leave also carries a heavy burden. “There are a number of things at the back of my mind, like my aging father. I might not be able to go back to see him if he has a problem and I try not to think about it,” he said.

Names have been changed to protect identities