There are thought to be one million migrant workers in Beijing
China's foreign minister has strongly criticised "anti-China forces" he says are determined to politicise this year's Beijing Olympics.
Yang Jiechi said individuals and groups were trying to tarnish China's image.
In recent weeks human rights groups and a number of Hollywood personalities, including Steven Spielberg, have stepped up criticism of China's record.
And a report by Human Rights Watch on Wednesday said migrant workers were being exploited to build a new Beijing.
HAVE YOUR SAY
"The Chinese government is all talk and no action when it comes to delivering meaningful protection and social services for migrant construction workers," said Sophie Richardson, of the New York-based rights group.
The Olympics is a sporting event and a chance for cultural exchange. So it's not fair to have activists use it as a political platform
Kai Hin Yung, Beijing
HRW said one million workers from other parts of China constituted almost 90% of Beijing's construction workforce.
Some workers had had their pay withheld for up to a year, the group said.
Mr Yang accused a few individuals and groups of wanting to politicise the Games.
"These people could never get their way. Those who want to tarnish the image of China... would only have their own images tarnished," the state news agency Xinhua quoted him as saying.
China sees the Beijing Olympics as key to its international prestige
These "anti-China forces" would be opposed by both Chinese people and the international community, he said.
He added that China welcomed "suggestion and criticism out of good will".
Beijing has come under fire for continuing to support the Sudanese government, which rights groups hold responsible for atrocities in the Darfur region.
Tibetan activists have also used China's hosting of the Olympics to publicise what they regard as China's occupation of their territory.