Brussels has unveiled new rules for companies trying to access public funds in strategic sectors including cars, green tech and steel, saying the firms must meet minimum thresholds for EU-made parts.

"We express serious concern and opposition regarding certain provisions of the proposal that may have far-reaching implications for market openness, fair competition, and China-EU economic and trade cooperation," the Chinese Chamber of Commerce to the EU (CCCEU) commented.

"The current design of the Act risks shifting toward a more exclusionary and protectionist framework."

Formally known as the "Industrial Accelerator Act", the EU proposal implicitly targets Chinese makers of batteries and electric vehicles, by requiring foreign firms partner with European firms and pass on technological know-how when setting up shop in the bloc.

The European Commission said the package aimed to reverse Europe's industrial decline and stave off hundreds of thousands of job losses.

European businesses in many of the sectors concerned by the proposal have long lamented they face unfair competition from heavily subsidised Chinese rivals.