On-the-ground views of China are troubling.

A analyst who just returned from a tour of China has a "gloomy" outlook.

"China's metals demand is plummeting," wrote Bloomberg Intelligence analyst Kenneth Hoffman, who met with executives, traders, industry groups and analysts. "Demand is rapidly deteriorating as the government slows its infrastructure building and transforms into a consumer economy."

It's a key time of year for infrastructure as commodity demand generally surges after the Lunar New Year but this year it has continued to decline. Iron ore prices delivered to the hub in Qingdao, China fell below $50/tonne in April.

If you like anecdotal views, it's no better.

"There is a big fear this is going to get worse before it gets better," Hoffman said in an interview. "It's as bad as the data looks, if not worse."

The PBOC could boost growth but so far they have remained on the sidelines, preferring to let the economy adjust rather than pumping up another credit bubble. Chinese CPI data is due at 0130 GMT and the consensus is a fall to 1.3% y/y but it will take a further decline to spur the PBOC to action.