“In the past, we sporadically had parents come to our sharing sessions. In these two months, the percentage of parents in Hong Kong who came increased quickly. They also came to us through different channels, such as recommended by friends, or they came in groups,” she told the South China Morning Post.

Mainland Chinese students flee Hong Kong fearing they will be attacked next

Gao said until recently parents had consulted the school – which caters for children aged three to 18 – for transfers when they had job changes or doubts about Hong Kong’s education offering. But, until recently, she had rarely seen people come in groups.

Most people who consult the school these days were firm that they wanted to move back to Shenzhen as a long-term strategy, she said. Gao said the reasons varied, from safety concerns to whether their children would be treated equally, or even bullied at school.

“As protection for their children and strategic planning for the family, they would consider moving. Shenzhen being just across the bay is the most direct and closest point for the backflow,” she said.

Indeed, parents have been discussing the transfer more urgently now than when protests first began in June, said a woman surnamed Zhu. Her family moved from Shenzhen to Hong Kong eight years ago, and her two children are attending elementary and high school there.

“I have not yet thought about transferring my children, but a friend is already planning to,” she said. “Because of the protests she couldn't stand living in Hong Kong any more.”

Zhu said her biggest worry was that children brought up in Hong Kong might have different values and sense of identity to their parents, such as what it means to be Chinese. Others reached by the Post expressed concerns about safety.

One woman who lives in Shenzhen with her husband said she did not want her son to travel to Hong Kong every day for school. Similar concerns are discussed by parents in social media groups more frequently lately, but not many have taken action because the school year is in the middle of a semester and tuition needs also must be considered.

For years, thousands have crossed the border to travel from Shenzhen to Hong Kong for school each day. These include children of Hongkongers living in mainland China, but most are mainlanders whose children earned residency by birth.

Latest estimates by Shenzhen Customs say there are more than 30,000 cross-border pupils who each day spend three to four hours travelling to study in kindergartens, primary and secondary schools in Hong Kong.

Students’ future hangs in the balance in Shenzhen, China’s Silicon Valley

But in recent years Shenzhen’s education scene has developed with international schools becoming more common in the city, which has always been criticised for its lack of quality education, medical services and daily conveniences, despite its reputation as a hi-tech powerhouse.

Coupled with the latest trend of a backflow from Hong Kong in recent months, Shenzhen’s international schools are taking the opportunity to win more parents disaffected with their children’s long commute and the continuing unrest in Hong Kong.

Whittle is holding an open house this month to demonstrate to these parents why schooling in Shenzhen may better suit their children’s needs and other international schools in Shenzhen are offering similar sharing sessions or programmes.

One of these, Merchiston International School (MIS) was the first in Shenzhen to provide a British education and boarding system when it opened in August last year for students aged four to 18. Its students must have foreign ID or residency in Hong Kong, Taiwan or Macau.

In late November, MIS will start offering free trial classes for children who have passed its rigorous entry-level tests, targeted specifically at “cross-border students” who live in Shenzhen and travel to and from Hong Kong for school.

An MIS spokeswoman said that, without the time spent travelling each day, students would be able to take part in more extracurricular activities such as music, sports and art.

“Besides, Merchiston follows the British National Curriculum with 80 per cent western teachers – a curriculum that is often used across the border,” she said.

For parents like Zhu, there is time to wait and observe for a little longer to see if changes in Hong Kong’s education system will address her concerns.

“Right now, my children are starting to learn Chinese history at school. That wasn't there before. I think there's still hope,” she said.