By Duncan Hewitt BBC correspondent in Shanghai

An official Chinese newspaper has published one of the country's strongest criticisms yet of Taiwan's President Chen Shui-bian.

A commentary in the English-language China Daily described Mr Chen as a "troublemaker" and a "devout warrior for an independent Taiwan", who sought "only discord" in relations with Beijing.

Beijing has clearly been alarmed by what it sees as moves by the Bush administration towards unambiguous support for Taiwan

China has until recently reserved its judgment on Mr Chen - a long time pro-independence politician who stunned Beijing by winning Taiwan's elections two years ago.

Yet this attack may indicate China's growing concerns - amid signs of strengthening US support for the island.

Since Chen Shui-bian's shock election victory two years ago, China has taken a cautious line, sticking to what it calls a policy of listening to his words and observing his actions.

Mr Chen, for his part, has called for talks with Beijing and pledged not to declare Taiwan's formal independence from the mainland - from which it has been separated since China's civil war in 1949.

'Reneging'

Yet the China Daily's commentary said Beijing now believes his words are just for show.

It said his behaviour had made it clear that he remained a warrior for an independent Taiwan.

And it accused him of reneging on a key 1992 consensus between the two sides that Taiwan is - and should remain - a part of China.

China regards Taiwan as a renegade province

The paper also attacked Mr Chen for what it said were his efforts to court foreign sponsorship and beef up Taiwan's military.

Beijing has clearly been alarmed by what it sees as moves by the Bush administration towards unambiguous support for Taiwan - including in the event of a military attack by China, which still reserves the right to use force against the island.

The article may well be a warning to Washington, designed to coincide with the current visit there by China's Vice-President Hu Jintao.

Pull of trade?

Significantly, the article said Mr Chen had inherited the mantle of "troublemaker" from his predecessor Lee Teng-hui - a man much reviled in China, particularly by hardliners in the country's military - as an arch-separatist.

The China Daily lashed out at Mr Chen's moves to stress a distinct Taiwanese identity in education and society.

"His audacity in ignoring both history and reality is outrageous" it said, accusing him of taking over from Lee Teng-hui as the "cheerleader of de-Sinicization" and of seeking to erase references to China and Chinese heritage in the island.

But it is not yet clear whether these remarks mean China has given up hope of starting a dialogue with Mr Chen.

In the complex world of China-Taiwan relations, analysts said the comments could be an attempt to keep up pressure on the Taiwanese president to open direct trade links with the mainland, amid rapidly expanding economic links between the two sides.