Born in Hong Kong to mainland Chinese parents just half a year after China was taken over by the Communists, Ma and his family moved to Taiwan when he was one year old.

After studying at New York University and Harvard University Law School, he had a brief stint on Wall Street, before returning to Taiwan and rising quickly through the ranks of the Nationalists, who ruled China before the Communist takeover.

Now 57, he was the Nationalist Party's (KMT) youngest deputy secretary-general at the age of 33 and Taiwan's youngest justice minister at 43.

A few years later, Ma unseated the Democratic Progressive Party's Chen Shui-bian, the current president, as Taipei mayor in 1998.

The avid jogger's good looks and normally snappy dress sense have been known to send female supporters into a swoon, though his enemies charge that he is all style and no substance.

"Ma is known for his decency, integrity and honesty. The DPP campaign is trying very hard to knock him off that pedestal, to create an impression that Ma is somehow untrustworthy or tainted," said George Tsai, an international relations professor at National Chengchi University.

"Those efforts have tarnished his credibility to some extent, but the impact appears to be waning," Tsai said.

DPP presidential candidate Frank Hsieh has attacked Ma for being born outside Taiwan and that he once held a U.S. green card, implying that he could flee Taiwan in a crisis.

Ma insists his green card expired long ago.

Ma, who media opinion polls suggest will win the presidency, wants stronger business ties with China and favours eventual reunification with the mainland if Beijing democratises, sparking concern he might cosy up too closely to the Communists.

He wants to widen commercial ties with China, including relaxing an investment cap and opening the island wider to Chinese tourism and charter flights.

His China trade agenda dovetails with domestic pledges of six percent annual GDP growth, $30,000 GDP per capita and a jobless rate of less than three percent.

But a President Ma would be keen to show he can stand up to China and not be seen to be "selling out" Taiwan, analysts say. He is in favour of maintaining the status quo in relations with China and said he would not push for Taiwan independence or reunification with China if elected.

"Ma is flexible on economic links, but tough on political links," said Dafydd Fell, lecturer in Taiwan Studies at the School of Oriental and African Studies in London.

Ma denounced comments this week on Taiwan by Chinese Premier Wen Jiabao, who offered to resume talks under the "one China" principle. Ma said Taiwan's future could only be decided by the island's 23 million people.

"The earlier statement made by Wen Jiabao, Premier of the People's Republic of China, was rude, unreasonable, arrogant, absurd, and self-righteous," Ma told reporters.

China has seen self-ruled Taiwan as part of its territory since the civil war ended in 1949 and threatened to use force, if necessary, to bring the island under its control.