The EU's trade relationship with China is "deeply unequal", its trade commissioner Peter Mandelson has said.
Mr Mandelson said the public wanted trade to be fair
In a frank letter to the European Commission president, seen by the BBC, he suggested that China took business in Europe for granted.
China is now the EU's biggest source of manufactured goods.
But Mr Mandelson said that tariff barriers and Chinese interventions were limiting how much the EU sold to the Asian giant - costing firms billions.
The letter added that the Chinese were "procedurally obstructive" where dialogue had been set up.
The EU sold more goods to Switzerland than it did to China, the letter to Jose Manuel Barroso said, adding that the trade deficit between the EU and China was growing at about £10m every hour.
"The Chinese juggernaut is, to some extent, out of control," Mr Mandelson added.
The BBC's Jonny Dymond, who has seen the letter, says that the trade commissioner 's letter "effectively accuses China of taking the mickey".
"The message behind the letter looks pretty clear - that Europe has rolled over long enough," our reporter added.
Separately, Mr Mandelson told the BBC that pressure from the public and politicians for a level playing-field of trade was growing.
"If we want to sustain a policy of openness towards China politically, we have to make sure that the public is satisfied that that trading relationship is being conducted on full and fair trade, otherwise we are going to be in trouble."
China was "shifting the economic and diplomatic scenery so fast that it is almost impossible for policy makers to keep up let alone be ahead of the game", he added.
"Because of China's extraordinary economic growth as well as its political and diplomatic reach, and the effect it can have on global security, we are seeing China changing the whole global landscape in so many different ways."