The proposed sale of a rare bronze statue, looted from Beijing by British and French soldiers in 1860, has run into powerful opposition from China, where there is rising anger over the millions of Chinese antiquities held by foreign museums and collectors.

The beautifully preserved bronze horse head, which originally adorned the summer residence of China's ancient emperors, will be the centrepiece of Sotheby's autumn auction in Hong Kong next month. It is expected to fetch up to £5 million.

But China is becoming increasingly vocal about its lost antiquities: more than 1.6 million pieces are in museums in 47 countries, according to Unesco, the United Nations cultural organisation, and millions more are believed to be in the hands of private collectors.

Many Chinese regard foreign ownership of their cultural relics, especially those plundered by the former colonial powers in the 19th century, as a humiliating reminder of a weaker past.

Now, officials of China's Fund for Rescuing Lost Cultural Relics from Overseas have vowed to try to stop the sale and are demanding that the statue be removed from open auction.