China has unveiled a new anti-secession law that gives Beijing the legal basis to launch an offensive against Taiwan as a last resort.

National People's Congress Vice Chairman Wang Zhaoguo announced the provisions of the law at the annual session of the congress Tuesday. Mr. Wang said the anti-secession law seeks to carry out the Communist leadership's long-promised goal of reunifying Taiwan with the mainland.

Quoting the bill, he said the law allows Beijing to use non-peaceful means if there are - in the words of the text - "major incidents" to bring about the formal separation of Taiwan from the mainland.

Mr. Wang says that if possibilities for a peaceful reunification are completely exhausted, the state will employ non-peaceful means and other necessary measures to protect China's sovereignty and territorial integrity.

Following the unveiling of the measure Tuesday, the government in Taipei issued a strong protest saying the law violates Taiwan's sovereignty and is in effect a "blank check" for the mainland to use military force against the island

The peaceful reunification method proposed by Beijing is the so-called "one country, two systems" model imposed on Hong Kong when it reverted to Chinese sovereignty in 1997, but consistently rejected by Taiwan.

The new anti-secession law makes provisions for peaceful reunification, through, for example, closer economic ties, such as the establishment of direct transport links between Taiwan and the mainland.

Deputies are expected to approve the law next Monday at the conclusion of the NPC session.

Its drafting comes after months of rising tensions triggered by what Beijing interprets as Taiwanese moves toward independence.

Taiwan, now a democracy, has been ruled separately since 1949, when Nationalists fled to the island following their defeat to the Communists on the mainland at the end of the Chinese civil war. Since then, Beijing has vowed to reunite Taiwan with the mainland by force if necessary.

The Taiwan issue has been a ready source of Chinese rhetoric over the past 56 years, but the passage of the law is a new concrete indication of Beijing's resolve to go to war if the island secedes.

NPC Vice Chairman Wang's explanation of the law Tuesday contained some finer points, including tactics that China would employ if it carried out an attack on the island.

Mr. Wang says, the state shall exert its utmost to protect the lives, property and other legitimate rights and interests of Taiwan civilians and foreigners in Taiwan, and minimize losses.

The law has triggered alarm in Taiwan, where thousands demonstrated against it on Sunday. More demonstrations are planned.