'Their plan is ridiculous,' Yao said. 'Can't they show some respect for our culture? The United Nations says cultural diversity should be preserved because it is mankind's heritage.'

Yao need not have worried about support for his plea. More than 80 per cent of the 30,000 respondents to a survey by the Guangzhou committee of the Chinese People's Political Consultative Conference opposed the plan.

However, local authorities were not listening as they prepare to host the Asian Games in November. Guangzhou Television decided to make the switch after the Guangzhou CPPCC on Monday recommended that visiting athletes and spectators should be able to enjoy programming on the two channels in a language more widely understood.

In a bid to reassure local viewers, officials said later that the broadcaster, which operates nine channels, would continue to broadcast most of its programmes in Cantonese.

Defenders of Cantonese can take heart from the knowledge that the last time the station opted for more Putonghua programming, ratings fell and it was forced to switch back.

Before the survey result was announced, a spokesman for the Guangzhou CPPCC explained why it was important to enhance Putonghua programming in time for the Games.

'Many people will be visiting us during the Asian Games,' he said. 'They don't understand Cantonese. We should cater to their needs when they are in Guangzhou.'

Most media outlets on the mainland are banned from broadcasting in regional dialects as part of efforts to entrench the use of Putonghua, but Guangdong is an exception because it is easy for local residents to tune in to Cantonese broadcasts from neighbouring Hong Kong. A ban on Cantonese could simply force more viewers to switch to Hong Kong stations.

Guangzhou Television has been the only all-Cantonese media outlet in the southern city. Other media outlets, such as the provincial-level Guangdong Television and Southern Television, split their channels between Putonghua and Cantonese broadcasts.

Ji Kekuang, a member of the Guangzhou CPPCC, was behind the move to increase Putonghua broadcasts by the local station.

'We are talking about a harmonious society,' he said. 'How can our television be so selfish as to cater only to the needs of locals?

'We have 13 million people in Guangzhou, and at least six million of them are immigrants. They don't understand Cantonese and we can't exclude them.'

Cantonese, which is spoken in Guangdong, Hong Kong, Macau and parts of the Guangxi Zhuang Autonomous Region , is regarded as a modern variant of the ancient Han language. In pronunciation, vocabulary and usage, it is very similar to the official language used during the Tang dynasty (618-907) and is a much older language than Putonghua, according to experts in linguistics.

To standardise Putonghua, officials decided to eliminate the indigenous usage and vocabulary of the Beijing dialect while including terms in wide use across the north, making the northern dialects the basis of the language.

As a result, Putonghua is not the native tongue of anyone, according to some experts who describe it as a linguistic artefact.

The government has stepped up efforts in recent years to promote Putonghua in Cantonese-speaking areas. Schools post banners reminding students of the importance of speaking Putonghua and equate the use of the national language to civilised behaviour. Some Guangzhou parents complain their children are now reluctant to speak Cantonese, even at home.

This assault on Cantonese is compounded by the increasing population of immigrants working and living in cities like Guangzhou.

Yao estimates the Cantonese-speaking community in the city has dwindled to less than half of the total population.

This influx of non-Cantonese speakers has changed the linguistic complexion of entire areas of the city. Tianhe , the central business district, is a predominantly Putonghua-speaking area, while the historic neighbourhood of Liwan retains the highest concentration of Cantonese speakers.

Even some of the migrants are sympathetic to efforts to preserve the local tongue. Kuang Xiaoyu, a Sichuanese who moved to Guangzhou six years ago, opposes Guangzhou Television's plan.

He understands Cantonese, although he prefers speaking in Putonghua. But, when speaking with people from his hometown, he switches to his local Sichuanese dialect.

'I value my native language,' he said. 'It is important for me to keep using it.'

Kuang described supporters of the change as 'barbaric' and said they should show more respect for the languages of the southern region. 'They can't ask people to shut up simply because they are in power and they have guns in their hands,' he said.

Critics believe that Guangzhou Television will soon get some clear signals as to how the audience views the change.

'If they force Guangzhou Television to switch to Putonghua broadcasting, I'm sure the viewers will turn to watching Hong Kong television,' Yao said.

Widespread opposition

Of 30,000 people surveyed, the proportion opposed to the switch to Putonghua was: 80%