The attack came when Chen showed up at the Taipei District Court as a defendant around 10 a.m. for the first hearing in a defamation suit involving the long-stalled Lafayette frigate procurement case, in what was his first court appearance since he left office on May 20.

The attacker, identified as Su An-sheng and a staunch member of the pro-union Concentric Patriotism Association of the Republic of China, kicked Chen before National Security Bureau guards could stop him.

Su was immediately whisked away to a police station for questioning. The police said Su would be referred to the Taipei District Prosecutors Office on charges of physical assault if Chen files a suit against him. Should the ex-president decide not to do so, the police will refer him to the Taipei District

Court on charges of violating statutes governing social order.

The opposition Democratic Progressive Party (DPP) soon condemned the National Security Bureau for failing to protect former President Chen Shui-bian, and urged President Ma Ying-jeou to make a statement on the incident.

"The incident, which occurred just two months after Chen left office, is a great insult to democracy and human rights, " said DPP Taipei City Councilor Chou Po-yia, after a news conference held by the DPP's Taipei City Chapter to call on the government to use donations for China's Sichuan earthquake for storm disaster relief in southern Taiwan.

Wang Tuoh, secretary general of the opposition DPP, said at a press conference yesterday afternoon that the violent behavior against an ex-President should be seriously condemned and punished, as it is really an insult to Taiwan's democracy.

Wang also urged President Ma to openly condemn the violence, lest such violent tendencies fuel confrontation between the different political camps.

Former DPP Legislator Kao Chien-chih said members of the Concentric Patriotism Association often behave irrationally and violently toward the pro-independence DPP.

"I really worry about the safety of Chen under such poor security measures," Kao said. "Given the fact that the anti-Chen complex shows no signs of dying down, the National Security Bureau should step up the protection of the former president."

Chen was summoned by the Taipei District Court to appear at the trial, as he has been accused by former Vice Admiral Lei Hsueh-ming, a former chief of the Navy's Shipbuilding Office, and four other ex-naval officials of defamation. The case arose from Chen's statement at a public function in December 2005 that Lei and several Naval officials had produced false performance data on Lafayette frigates and inflated the price of the vessels to manipulate the Navy's 1990 purchase of frigates from France instead of from South Korea as originally planned.

Chen said that Lei and other officials from the Shipbuilding Office had, after 1990, received US$20 million as commission, which the former president said "was a blatant indication of graft."

Chen said that after 1990, US$20 million was discovered in a bank account held by Lei, which was a blatant indication of graft.

But Lei rebutted Chen's claim and filed a suit against him.

Lei and five other military officials were indicted in 2001 on charges of receiving kickbacks from the French ship-building company that builds the Lafayette.

Taiwan bought the six frigates in 1991 at a cost of US$2.8 billion, of which around US$500 million was reported to be kickbacks paid to officials in Paris, Taipei and Beijing.

During Monday's trial, Chen reportedly defended himself as having made "rational comments" and "questioned suspicious points" in a case that has not yet been settled.

Chen said it was clear as daylight that there must have been more fingers in the Lafayette pie, as the NT$15 billion commission allegedly involved in Taiwan's US$2.8 billion purchase of six Lafayette frigates in 1991 could not have been bagged solely by the two people accused in the case.

The two are Wang Chuan-pu, an arms broker whose whereabouts remain unknown, and Kuo Li-heng, a former naval officer who is behind bars in Taiwan.

Chen said it took him by surprise that he has now become a "defendant" in a court case after his many years of trying to protect the country and its people's rights and interests.

He urged the judicial system to fight to reveal the truth behind the Lafayette frigate procurement scandal, so as not to allow those involved in the scandal to switch the attention of nationals from the case by filing defamation suits against an ex-President. "This is the biggest expectation of all nationals, and I would like to show up at the court for as many times as required, as long as the truth of the procurement scandal can come to light."