No sooner had China's Cabinet called upon the whole nation to be honest and credible than one of China's largest property firms sought in vain to defend its controversial sales advertisement that many customers claimed had violated the law.

On October 19, Premier Wen Jiabao presided over a conference of the State Council (China's Cabinet) to address, among other things, the glaring lack of honesty and credibility in China today.

"Lack of honesty and credibility not only disrupts economic and social progress, destroys market and social order, and damages social justice, but also harms the public interest and undermines national and civilizational progress," the State Council warned.

But this warning appears to have fallen upon deaf ears when it comes to one of China's largest real estate firms by market value, whose motto is "To treat customers with the honesty of a gentleman."

On the evening of October 27, the company as represented by Mr Tang Kezheng, the top customer service manager in Shanghai, failed utterly to honor its own corporate creed, to say nothing of professionalism. He was joined by a subordinate and a company attorney.

The company was asked by several dozen families (including my wife and I) who have bought apartments to explain the basis of the company's prediction - in a widely circulated sales brochure and on the site of sales - that a new subway line would likely open in 2013 near one of its residential projects in suburban Qingpu District.

Convenient access to a subway line, of course (if were true) would make the property more desirable, justifying a better price. And it was partly on that basis of transport that many families were encouraged to buy.

However, the company failed miserably to produce anything that qualified as legal evidence.

Both China's Advertising Law and Real Estate Advertising Law require an advertiser to provide accurate and authoritative sources for its advertising claims. In the case of predictions, there must be solid indicators, no wild guesses.

Here are the two "accurate and authoritative" sources Mr Tang and his colleagues provided to questioning buyers: 1. Information on Baidu Baike (literally meaning the encyclopedia of Baidu.com, China's leading search engine); 2. Phone conversations with "certain" officials of Qingpu District, where the residential project is located.

The attorney explained that he had searched Baidu.com and found a prediction of the subway likely opening around 2013.