I NSIDE AN AUSTERE room in an industrial building in Hong Kong, a dozen or so middle-aged women, many with small children by their side, arrange chairs in a circle. They are new migrants from mainland China who have come to attend a free Cantonese-language conversation course run by a local NGO . The youngsters, who have recently enrolled at local schools, are already near-fluent. Their parents, however, often find themselves reverting to Mandarin, their mother tongue, when the going gets tough. Each time this happens, the instructor, a native Hong Konger, politely reminds them to stick to Cantonese, even if it makes their children blush.

The border between Hong Kong and mainland China operates much like an international one and mainlanders are not free to enter the city at will. But up to 150 mainland Chinese are allowed to settle in Hong Kong every day under the one-way permit scheme, a programme set up in 1980 that lets mainlanders apply to reunite with relatives in the territory. Since Hong Kong returned to Chinese sovereignty in 1997, around 1m mainland Chinese have immigrated to Hong Kong in this way, accounting for 90% of the city’s population growth in recent years. One source of the influx is marriages between mainlanders and locals, which account for a third of all marriages registered in the territory, up from just 7% in 1996.

No territory is an island

The influx has helped to fuel a “localist” movement, whose members say they are campaigning to preserve Hong Kong’s way of life. Many natives take this to include a shared language and respect for the rule of law. One-way permit holders, in particular, arouse resentment. Locals blame them for pushing up house prices and taking school places; spreading bad manners such as spitting and talking too loudly; driving down wages and claiming welfare. Only 21% of newcomers aged 15 and over on the family-reunification scheme have been educated beyond secondary school, compared with 32% for the population as a whole. Barely half of adult one-way permit holders are in work.

A common belief among locals is that the scheme attracts too many poor and uneducated mainland women who will marry any Hong Konger, including blue-collar workers shunned by many native-born women, just to claim welfare in the city. And many Hong Kongers, including members of the local legislature, suspect that some mainlanders buy one-way permits from conniving officials for as much as HK$2m ($255,000) each. (The governments in Beijing and Hong Kong deny this.)

Identity politics also plays a role. Recent surveys by the University of Hong Kong show that growing numbers of locals identify themselves exclusively as “Hong Konger” rather than “Hong Konger and Chinese”, and would sooner call themselves “Asian” and even “global citizens” than “Chinese”. This stems in part from misgivings about the mainland’s interference in Hong Kong’s affairs. Pride in a distinct Hong Kong identity often descends into outright discrimination against mainlanders. In recent years young Hong Kongers have organised “anti-locust” rallies, waving placards blaming mainlanders for crowded shopping malls and restaurants.

A woman who moved to Hong Kong in 2008 from the north-eastern province of Jilin to join her husband says she suffered from “severe depression” during her first four years in the city, owing in part to the discrimination she faced. She recounts how street vendors mocked her Cantonese and commuters hurled anti-mainland epithets at her when, for instance, she veered off designated paths for pedestrians. Immigrants from neighbouring Guangdong province, where Cantonese is spoken, fare better in Hong Kong, notes a language instructor. Yet they, too, might benefit from taking additional Cantonese lessons to “correct their accent”, the instructor explains. “Hong Kong employers prefer those with local accents.”

Many mainlanders quickly become disillusioned with their new life in Hong Kong. Earlier this year Hong Kong’s home-affairs department conducted a survey of more than 6,000 one-way permit holders who have lived in the territory for less than a year. It found that nearly 60% had “difficulties adapting to life in Hong Kong” and a quarter had enlisted the government’s help in finding a job. This is despite the fact that two-thirds of one-way permit holders come from Guangdong, the Chinese province that is most similar to Hong Kong culturally and linguistically.

Zhang Fen, a former kindergarten teacher in the southern city of Guangzhou, the capital of Guangdong, could only find part-time work at McDonald’s and school canteens during her first few years in Hong Kong, although she does not attribute her travails to discrimination. She regrets falling out of the ranks of the xiaokang (moderately prosperous) class in Guangzhou and joining the diduan (lowly) stratum in Hong Kong. Greater personal freedom in the city, such as unrestricted internet access, cannot compensate for grimmer living conditions such as a bunk bed shared by four family members, Ms Zhang says.

Many new arrivals depend on the free services of local NGO s to help them settle in. One such is the HKSKH Lady MacLehose Centre, which offers drama classes to help migrants gain self-confidence. Mission to New Arrivals, a Christian non-profit, teaches newcomers arts-and-crafts and helps them to sell their creations. A vocational-training centre affiliated with the Hong Kong Association for Democracy and People’s Livelihood, a political party, trains migrants in trades such as housekeeping and massage. All instruction is strictly non-political, says an employee.

Hong Kong’s government also tries to stop politics intruding on the issue. Carrie Lam, Hong Kong’s chief executive, has repeatedly rejected the idea that she might try to negotiate a reduction in the daily quota of one-way permits with the authorities on the mainland. Instead, with a degree of prejudice similar to those she is denouncing, she has described locals who consider mainlanders a blight on the territory as “brainwashed”.