When people have enough to eat, they often start thinking about the finer things in life: Laphroaig, Lamborghini – and what language they speak to their children.

Mao Zedong thought mother tongues were a luxury that communism could ill-afford, so he tried to impose a common language: everyone had to wear Mao suits and speak Mao’s Mandarin. Teachers were forced to teach in it, and children were forced to speak it, even on the playground. Dialects such as Shanghainese – a language all but unintelligible to Mandarin speakers – was taken off the radio, television and out of the schools.

But now, after decades engaged in the single-minded pursuit of materialism, Shanghai is beginning to show interest in things other than money – such as the 700 year old language of its forebears. When Sina Weibo, the Chinese version of Twitter, recently asked whether local dialect should be used on public transport in Shanghai, 3m people weighed in on the topic. Some 75 per cent supported the local language.

In the past few weeks alone, Shanghai Airlines has started broadcasting in Shanghainese on several routes on a trial basis; as have some city buses; and at least one local primary school has given children the green light to speak patois on the playground, for the first time in a generation.

The older generation never stopped speaking vernacular: almost every Shanghainese old enough to have worn a Mao suit still speaks it when given the choice. But those born in the 1990s tend to have a tenuous grasp of it – often because their parents thought it was more useful to learn English. Those born this century hardly speak it at all. Though it is the mother tongue of at least 10m people – more than 10 times as many as speak Basque or Welsh, for example – Shanghainese is in danger of dying off.

Grandfather Shen Quanfa, 70, is delighted to find himself listening to the language of his childhood on his daily ride on the 785 bus. “Fewer and fewer people can speak Shanghainese,” he says in heavily-accented Mandarin.

His face beams with pride as a recorded female voice says “exit the bus from the rear doors please,” and other sweet nothings in Shanghainese.

Playground politics

But if there are 10m people in Shanghai who speak the vernacular, there are at least another 10m who do not – and most of them do not want to.

Shanghai’s people, and their language, are not wildly popular – even among other Chinese. Viewed as rude and pushy by foreigners, they are the Asian equivalent of New Yorkers – no one much likes them but other Shanghainese. It does not help that they always seem to be shouting at each other.

Thus many immigrants to Shanghai – who dominate the city’s white collar professions – consider the vernacular pride movement either unnecessary or unwelcome.

Fang Xumeng does not speak the local lingo, though she came to the city at age six. “Shanghai is already very xenophobic,” she says as she strolls through a subway tunnel, arm in arm with a friend. “That impression will just be strengthened if they broadcast in Shanghainese,” she says, referring to a proposal that the city’s metro system also introduce the vernacular.

Whose idea is this anyway? Not the government’s, says Qian Nairong, professor of linguistics at Shanghai University and a leading light of the pro-dialect movement. He says local government is divided between those who want to protect the lingua, and those who are afraid that Beijing will not like it.

The pro-vernacular forces are hardly proposing to launch a separatist movement: Mr Qian just wants children like his seven year old granddaughter to be allowed to speak the dialect at recess. But Beijing may think what happens on the playground today will happen in politics tomorrow: they unlikely to sanction a Republic of Shanghai anytime soon.

Demolition mayor

So Shanghai’s words may be getting some protection soon – but the same may not be said of its architectural history. Just as the bus company was launching Shanghainese broadcasting, the city’s mayor was pledging a dramatic acceleration in the “remodelling of old districts” – also known as putting money before culture. Some habits die hard.