TAIPEI (AFP) -- Taiwanese President Chen Shui-bian is likely to survive pressure on him to resign despite a mass rally which drew hundreds of thousands of people seeking his ouster, officials and analysts said.

The protesters took to the streets of Taipei Friday dressed in red to demand Chen's resignation in the wake of graft allegations implicating himself and his family.

Shih Ming-teh, the former head of Chen's independence-leaning Democratic Progressive Party (DPP) and leader of the anti-Chen campaign, said at least 750,000 people had turned out. Police estimated the crowd at 360,000.

Taiwan's politicians later appealed for calm Tuesday after some protests against the president led to violence.

Chen, who favors Taiwan's independence from China, has refused to bow to the pressure. He says he will remain in office until his second four-year term expires in May 2008.

But Friday's march rattled DPP politicians' nerves.

"The DPP should take the march seriously because a majority of them were women and youths, or the so-called middle class people (who) used to be cold to politics," legislator Chen Ching-chun, the DPP party whip at Parliament, told reporters.

The legislator said a "new civil social movement" had been emerging and demanding clean politics.

"The DPP should become more humble and listen carefully to their voices," he said.

The party issued an order last week mobilizing its supporters to rally behind Chen on Saturday. The organizers said up to 200,000 took part in the event in Taipei, but police estimated the turnout at 50,000.

Chen's supporters paint the campaign against him as a Beijing-inspired plot. Wu Tung-yeh, a professor at the National Chengchi University, said Shih would seek to keep the momentum of his campaign going "while anticipating a knock-out punch by taking the scandals to the law."

"The last blow may come should the DPP suffer a landslide defeat, which is very likely, in the December Taipei and Kaoshiung mayoral elections as well as the parliamentary polls next year," professor Wu said.

Emile Sheng, a spokesman for Shih's campaign, cited an unnamed source as saying that the investigator looking into the graft allegations would complete his probe before the end of the month.

The president has been under pressure to resign since his son-in-law, Chao Chien-ming, was detained and indicted on suspicion of insider trading and taking bribes. Chen has publicly apologized for Chao's actions.

The president survived an unprecedented parliamentary vote to topple him in June. The move failed to win the backing of two-thirds of all lawmakers. If passed, it would have triggered a national referendum on Chen's future.

His wife Wu Shu-chen is also under investigation for allegedly accepting department store gift certificates in exchange for lobbying efforts.

Chen, first elected in 2000 after more than 50 years of nationalist Kuomintang rule, narrowly won re-election in 2004 for a second and final term.