Taiwan's presidential candidates clashed over China policy during their first televised debate Sunday, ahead of elections in which relations with Beijing will be a key issue for voters.

Fears over Beijing's influence on the island have grown since a rapprochement under the ruling Kuomintang (KMT), culminating in a landmark meeting between current President Ma Ying-jeou and Chinese President Xi Jinping in November.

Public unease over closer relations is a major factor behind the KMT's dwindling popularity and sparked the occupation of parliament by protesters last year over a trade pact with China.

Tsai Ing-wen of the Beijing-sceptic Democratic Progressive Party (DPP), widely tipped to win the presidency in January, criticised the KMT for relying too much on China.

"We need to be comprehensively linked to the major global economies, and not just solely tied to China," she said, arguing that the KMT had only given Taiwan "one option".

But she trod carefully when it came to political relations with Beijing.

"Everything can be discussed," she said.

"This is a rational approach and I believe China will also take a rational attitude in interactions with DPP."

Tsai has consistently said she will not rock the boat with China if elected, but has been slammed by the KMT for being unclear on her strategy.

"Tsai said she will not provoke China and there will not be surprises, but she is still being vague," her KMT opponent Eric Chu countered.

He also defended the KMT's China policy.

"China is not our only option but we should not oppose everything China-related," he said.

Taiwan is self-ruling since a split with the mainland in 1949 after a civil war, but has never formally declared independence. Beijing sees it as a renegade province awaiting reunification.

Beijing insists any new leader must recognise the "1992 consensus" -- a tacit agreement between the KMT and China which says there is "one China" with different interpretations.

The DPP has never recognised the agreement and Tsai remained circumspect Sunday.

"I believe cross-strait relations can remain stable... the 1992 consensus is an option, but it's not the only one," she said.

Some analysts said she was taking a softer line, assuaging China and major ally the United States, which does not want to see increased tension in the region.

"She is sending a message not only to voters in Taiwan but China and the US that she is willing to communicate," said Shih Cheng-feng, a political analyst at National Dong Hwa University.

Others said there was little concession.

"She says nothing about 'one China' which is the crucial part of (the) 1992 (consensus)," said Jonathan Sullivan, a China specialist at the University of Nottingham.

Third presidential candidate James Soong of the China-friendly People First Party (PFP) said China and Taiwan should "seek common ground", but urged Beijing to respect Taiwan's sovereignty.

Soong, a conservative political veteran, is trailing both Tsai and Chu in the polls.