By Rupert Wingfield-Hayes
BBC News, Beijing
With the Beijing Olympics now only two years away, the authorities have launched a campaign against one of the city's least pleasant habits: spitting.
China has tried before to encourage the public to stop spitting
The local government says it is part of a campaign to raise the ethical and cultural standards of the city ahead of the 2008 Games.
Foreign visitors to Beijing are often astonished by its citizens' capacity for expelling mucus.
Spitting is not just confined to the open air.
The floors of shops and restaurants are often peppered with phlegm.
But Beijingers are now being told they must abandon this cherished tradition.
The Beijing Capital Ethics Development Office has declared spitting the city's number one bad habit.
Police have been ordered out on to the streets to track down offenders. Closed circuit television cameras will be used to catch them in the act.
"This year we will intensify our law enforcement efforts in this field," Zhang Huiguang, director of Beijing's Capital Ethics Development Office, told a news conference.
"We will require law enforcement officials to step up the frequency of fines."
For those who simply cannot kick the habit, there is an alternative. Hundreds of uniformed "mucus monitors" will patrol the streets handing out free spitting bags.
"You have to spit into a tissue or a bag, then place it in a dustbin to complete the process," Ms Zhang said.
She said that there would also be a renewed crackdown against the city's second biggest headache - littering.