A Chinese mainland official on Friday lashed out at Taiwan leader Chen Shui-bian's latest plan for so-called "constitutional reform" and warned that the move would cause instability in the region.

In a reported interview, Chen said he would propose a "freezing" of Taiwan's existing "constitution" and apply a new one that suited Taiwan's current situation.

"It is another dangerous move of Chen to serve his own interests. His words will stir up opposition on the island and cause trouble on developing the relationship across the Taiwan Strait," said a spokesman of the Taiwan Affairs Office of China's State Council.

"If Chen is allowed to audaciously push forward the reform, it will threaten China's sovereignty and territorial integrity, the development of cross-Strait relations, and the peace and stability of the Strait or even the Asia-Pacific region at large," the spokesman said.

The Chinese government firmly opposes Chen's plot to achieve Taiwan's "de jure independence" through "constitutional reform", he said.

On Sept. 24, Chen raised the issue of "constitutional reform", which involved the possibility of changing the "territorial definitions" of Taiwan. Mainland officials have criticized the plan from the outset.