China has been forced to strongly deny claims made in a new Pentagon report that it is the world’s number one cyber spy and represents a growing threat to US economic security.

Foreign ministry spokesman Hong Lei expressed “firm opposition” to the report and said “China's justified and normal military development" had been unjustly criticised by the US, according to state-run news mouthpiece Xinhua.

The report, issued on Friday, is the latest in a series of US military documents highlighting concerns with China’s long-term military modernisation efforts.

It alleges that the People’s Republic has leveraged “legally and illegally acquired dual-use and military-related technologies to its advantage” and, echoing a Northrop Grumman report out in March, points to “a long history of cooperation between its civilian and military sectors”.

Companies such as Huawei, Datang, and Zhongxing “pose potential challenges in the blurring lines between commercial and government/military-associated entities”, the report continued.

The Pentagon estimated China’s military spending for 2011 could have reached $180bn – a much higher figure than that quoted by Beijing – as efforts continue “to take advantage of what they perceive to be a ‘window of strategic opportunity’ to advance China’s national development during the first two decades of the 21st century".

In one of the most damming excerpts from the report, the Pentagon had the following:

Chinese actors are the world’s most active and persistent perpetrators of economic espionage. Chinese attempts to collect US technological and economic information will continue at a high level and will represent a growing and persistent threat to US economic security. The nature of the cyber threat will evolve with continuing technological advances in the global information environment.

Clearly, US intelligence has advanced to the point now where it can be pretty certain that cyber espionage attacks on its networks have been carried out, if not directly by Chinese military then certainly by “Chinese actors”.

The rhetoric has certainly been stepped up in recent months.

Aside from the Northrop Grumman report - which argued that Chinese commercial tech entities could pose a national security risk, and provide an “advanced source of technology” for the military - a report last month recommended the tightening of certain hi-tech exports to China.

Foreign ministry spokesman Hong Lei reportedly argued that the US should be building mutual trust and co-operation and demanded it "respect facts, change its mind-set and stop its wrongdoing in issuing similar reports year after year”.

US officials could be forgiven for thinking the Chinese spokesman was directing those sentiments at his own employers.

After the high profile escape of human rights lawyer Chen Guangcheng last week, parts of the Chinese media argued that the US should stop encouraging Chinese citizens to flee the country - in a similar obstinate stance that ignores the basic rule of cause and effect. However, in a nation where ordinary folk only get to hear one side of every story, both arguments are unfortunately likely to be accepted without question. ®