BEIJING, Nov 28 (Reuters) - China will start a renewed push against illegal slaughterhouses and the sale of diseased, spoiled and doctored pork as part of a campaign to ensure food safety, the Commerce Ministry said on Wednesday.

Scandals involving substandard food and medicines are reported by Chinese media almost every day, and the issue has burst into the international spotlight since tainted additives exported from China contaminated pet food in North America.

China's pigs have been battered by an outbreak of blue ear disease, or Porcine Reproductive and Respiratory Syndrome, that killed as many as a million last year, though the government says infections have fallen after a vaccination campaign.

The outbreak contributed to soaring domestic pork prices and put pressure on national inflation levels, prompting Premier Wen Jiabao to visit a pig farm where he pledged to ensure meat for the poor of the pork-loving nation.

The Commerce Ministry, together with the health and agriculture ministries and police, will step up checks to make
sure no illegally slaughtered pigs or tainted pork find their way into the market, it said in a statement on its Web site
(www.mofcom.gov.cn).

"Strike hard against illegal abattoirs, the sale of meat injected with water or diseased and other illegal behaviour," it
said. "Resolutely crack major cases, and stop meat entering the market which has not been inspected."

The government unveiled a similar plan over the summer, suggesting problems remained in the system which still needed to be tackled.

Vice Premier Wu Yi, China's "Iron Lady" who is leading the effort to stamp out tainted and dangerous products, earlier this month lamented that many farmers had little idea about food safety and were still using underground slaughter houses.

This week, EU Trade Commissioner Peter Mandelson told China its reputation was at risk after a series of food and product safety scandals and that it must do more to tackle the problem.

Public fears about food safety grew in China in 2004 when at least 13 babies died of malnutrition in the eastern province of Anhui after they were fed fake milk powder with no nutritional value.