Taiwan's two leading presidential candidates have much in common: both are products of prestigious foreign universities, both come from well-established families, and neither is particularly charismatic.

But that's where the similarities end. Incumbent Ma ying-jeou wants Taiwan to move closer to China while contender Tsai Ing-wen refuses to accept China's claim over the democratic island.

As the final month of campaigning began Thursday, their neck-and-neck race will be closely watched by Beijing and Washington even though the Jan. 14 poll has so far revolved mostly around domestic economic issues.

"It's basically coming down to choosing the lesser of two evils," said Taipei teacher Stanley Ho, 47. He said he has yet to make up his mind, largely because he can't get too excited about either.

Chinese and American interest is keyed to the question of whether Ma will be able to continue his signature China policy, which in the past 3 1/2 years has lowered tensions across the 100-mile- (160-kilometer-) wide Taiwan Strait to their lowest level since the Taiwan and the mainland split amid civil war in 1949.

Ma's main emphasis has been on tying Taiwan's high-tech economy ever closer to China's lucrative markets, mostly through a series of ambitious initiatives including a far-reaching tariff slashing agreement, and the launching of hundreds of weekly cross-strait flights.

This has delighted Beijing, which sees in Ma its best hope of promoting its long held policy of bringing Taiwan under its control, not least because of his declared willingness to consider entering into political talks if he is re-elected.

It has also pleased the United States, because it regards a continuation of good cross-strait ties as a key to regional peace and economic development.

In the current race, Beijing clearly favors Ma, while the U.S. says it is neutral. However, some senior officials in the Obama administration appear to share Beijing's anti-Tsai bias, despite her repeated efforts to take a moderate stance on the China issue and distance herself from the robust support for formal Taiwanese independence that has characterized her Democratic Progressive Party in the past.

Recent opinion polls say the race is a virtual dead heat.

Ma, 61, who has a Harvard law degree, had a solid, if not altogether distinguished, record as justice minister and mayor of Taipei, and a somewhat remote personality that makes it difficult for him to connect with people outside his inner circle. His father was a mid-level official in the Nationalist Party that Ma now heads.

Tsai, 55, the scion of a wealthy family from southern Taiwan, was educated at Cornell University in New York state and the London School of Economics. She has served as the head of the government agency that oversees dealings with mainland China and as a vice-premier in the previous government. She acknowledges having some difficulty in unleashing the passion in DPP supporters that many take as their due.

"I voted for the DPP last time but this time I'm not too sure," said Jason Lin, a 36-year-old engineer from the southern city of Kaohsiung. "In the end I think it will come down to whoever I think will handle the economy better. For me, the economy is the main issue."

Early on in the campaign Ma stumbled over his assertion that he might work toward the signing of a peace treaty with Beijing if re-elected. That alarmed many Taiwanese voters, the majority of whom are enthusiastic about closer economic relations with Beijing, but want no part of a formal political relationship, because they fear it would undermine their hard-won democratic freedoms.

Ma has also come under attack for his economic policies, which Tsai alleges have spurred income inequality, and made it difficult for young Taiwanese to afford decent housing.

But Ma has hit back forcefully, insisting that a Tsai victory would lead to a resurgence of the cross-strait tensions that proliferated during the eight-year presidency of Ma predecessor Chen Shui-bian, the disgraced DPP politician who is currently serving a lengthy prison term after his conviction on corruption charges.

Ma's Nationalist backers also raised questions about Tsai's own probity, alleging that she profited from her interest in a biotech company that she allegedly helped establish while serving as vice-premier under Chen.

But after a DPP-initiated analysis of company documents, a senior Ma official was forced to acknowledge that that the date on a key document had been in error and Tsai's connection to the company began only after she left government service. The DPP labeled the error a deliberate forgery and called for Ma to apologize.

The case took a further turn on Wednesday after prosecutors announced they were looking into the company's formation, a move the DPP immediately slammed as a transparent attempt to enlist the machinery of government to undermine Tsai.