Chinese housing prices rose in May by 6.4 per cent, the fastest year-on-year monthly increase in 18 months, in the latest sign that the economy is outpacing both the government's and the market's expectations.

The World Bank and Morgan Stanley in recent days have revised upwards their growth forecasts for 2007 to above 10 per cent, bringing them into line with a fresh consensus for higher output this year.

Most predictions at the start of 2007 tipped growth of under 10 per cent, but such estimates seem conservative after a first quarter of 11.1 per cent and signals across the economic spectrum of accelerating growth.

“The latest data indicate buoyant activity in almost every aspect of the economy, including investment, retail sales, external trade, and industrial production,” said Qing Wang, of Morgan Stanley.

One of the most disturbing signs for the government has been the surge in power consumption, now rising at about 16 per cent annually, well ahead of overall growth.

The rise in coal-intensive energy consumption is a direct result of the persistent high investment in heavy industry, even though the government has pledged for three to four years to scale it back.

The World Bank said in its last China economic report that heavy industry investment remained high “under a policy setting that underprices . . . land, energy, resources and the environment”.

The increase in housing prices follows a similarly familiar story, of a market that remained impervious to a slew of noisy policy initiatives from Beijing to cool prices.

“Given the current market situation and the government's attempts to slow housing price rises, this increase is really shocking,” said Jason Yang, of Colliers International in Beijing.

In the capital itself, prices rose 10.4 per cent year-on-year in May, prompting the government to announce an investigation into the real estate market by eight departments.

“If the government really wants to lower property prices, it should increase land supply for the middle and lower-range market segment,” Mr Yang said. But the government has been doing the opposite, because of fears that real estate projects are eating into the country's declining stocks of arable land, at the expense of rural production and farmers' livelihoods.

Wen Jiabao, the premier, said after a special cabinet meeting last week that macro-economic controls should be “tightened” to prevent “overheating”.

But the government's response is complicated by the political calendar, with the lead-up to the five-yearly communist congress in late October raising the stakes in any policy clash.

Rising inflation, which hit a 27-month high of 3.4 per cent in May, is another worrying sign for Beijing.

The increase has been blamed on food, especially a shortage of pork, China's staple meat, because of a disease that killed many pigs late last year and the rising cost of feedstock. But rising housing prices and other cost pressures are starting to push up inflation as well, according to economists.

The government is expected to increase interest rates, possibly twice before the end of the year, but its bedrock policy of keeping China's currency stable constrains action on this front as well.