Image caption Implementing the one-child law has been hugely controversial

China is to overhaul the sometimes threatening slogans used to enforce its one-child policy, the authorities have announced.

Details of the project were published in the Chinese communist party newspaper, the People's Daily.

State media blamed local officials for coming up with phrases such as, "If you don't get sterilised, your house will be demolished".

They said they would be replaced by friendlier expressions.

But they insisted that the one-child policy itself would not change.

The Chinese Communist Party has long appreciated the value of the concise, direct political slogan, but in matters of family planning, street banners and wall posters are frequently seen as lacking tactfulness and taste.

'Kill your family'

Research by China's National Population and Family Planning Commission, published in the People's Daily, concluded that a quarter of slogans posted in furtherance of its policies had been crude and harsh in the past. It described some as spine-chilling.

Among the examples it cited were, "Kill all your family if you don't follow the rule" and, "If you escape (sterilisation), we'll hunt you down; if you want to hang yourself, we'll give you the rope".

The research said milder expressions should be used to "avoid offending the public and stoking social tensions".

For the past three decades, most Chinese couples in urban areas have been limited to having a single child.

Implementing the law has been hugely controversial, and has frequently involved sterilisation and even forced termination.

The one-child policy has also been blamed for causing a gender imbalance, with families eager to have male children and selectively aborting girls.

The People's Daily said future propaganda would address this issue, and suggested the slogan: "Caring for the girl means caring for the future of the nation."

Upbeat slogans were also mooted to prevent birth defects. The paper said one new slogan would be: "Please get rid of the alcohol and cigarettes before you plan to be a father".