China's top newspaper on Wednesday accused US lawmakers of "passing the buck" over America's economic problems with a bill to punish Beijing for alleged currency manipulation.

A commentary in the People's Daily -- viewed as the Communist Party mouthpiece -- said the bill was an attempt by lawmakers to cover up their inability to resolve America's economic difficulties.

"Faced with the discontent of the American people, some US lawmakers are using the Chinese currency to pass the buck over their political incompetence," said the article.

"Even those Americans who advocate renminbi appreciation have to acknowledge that a rise in the yuan's value is not a panacea to the US economic problems," it continued, using the official name for China's currency.

The US Senate this week pressed ahead with the legislation, which would empower businesses and in some cases labour unions to trigger a Commerce Department investigation into alleged currency manipulation.

Lawmakers of both major US parties charge that China keeps the yuan unfairly cheap against the dollar, giving its goods as much as a 30 percent edge over comparable US products.

But Beijing has let the yuan rise against the dollar as it faces stubbornly high inflation at home.

On Tuesday, Chinese foreign ministry spokesman Ma Zhaoxu said the proposed US measure amounted to "protectionism", while China's central bank also expressed "regret" at the bill.

"We think there are many reasons for global imbalances, and the yuan exchange rate is not the main reason for the Sino-US trade imbalance," the bank said in a statement.

"The differences in Chinese and US investment and trade structures, in deposit and consumer rates... and the unreasonable global currency system may be even more important elements than the currency exchange."

China's official Xinhua news agency went further, with a commentary on Wednesday in which it accused US lawmakers of using the country as a "political scapegoat".

"They would resort to China bashing for political gains and try to find a political scapegoat so as to shed their responsibilities for failure in dealing properly with domestic problems," it said.

In the United States, Republican House Speaker John Boehner also came out against the bill.

"It's pretty dangerous to be moving legislation through the United States Congress forcing someone to deal with the value of their currency," Boehner told reporters on Tuesday.

"This is well beyond what Congress ought to be doing, and while I've got concerns about how the Chinese have dealt with their currency, I'm not sure this is the way to fix it."

The US business community also mostly opposes the measure, citing concerns about embroiling the US in a trade war and about the impact of a rising yuan on the price of commodities and other inputs upon which US firms rely.

But US politicians have come under pressure to take on China ahead of 2012 elections shaped by anger at stubbornly high US unemployment, and backers of the bill say it stands to create millions of jobs.