A senior figure in Taiwan's governing nationalist party, the KMT, has resigned after admitting having an extramarital affair with a woman interior designer.

John Chang was secretary-general of the presidential office - a post he'd held only for a few weeks after being switched from the position of party secretary-general.

His departure comes as the campaign for presidential elections in March shifts into a higher gear, with the KMT's candidate locked in a bitter struggle with key rivals.

Deep regret

Flanked by his wife throughout an emotional news conference, John Chang described his infidelity as the greatest regret of his life, and offered his profound apologies to society.

The episode is believed to be the first such disclosure by a senior official of the KMT, let alone one so close to the core of Taiwan's elite.

Mr Chang is an illegitimate son of the late president, Chang Ching-uo, who was himself son of Generalissimo Chiang Kai-shek.

Clearly the party hopes the speed with which the resignation was offered and accepted by President Lee Teng-hui will help to diffuse the political impact.

Financial scandal

The incident had shifted the focus of attention away from a deepening financial scandal surrounding one of the key candidates in presidential elections in March, James Soong.

Mr Soong, himself a former top party official, was expelled from the KMT after deciding to run for president against the party's favoured candidate, current Vice-President Lien Chan.

Mr Soong has been accused by the party of stashing away billions of dollars of KMT money in private bank accounts in the early nineties.

Bitter feud

He has retorted that the money was entrusted to him by President Lee, who was his political mentor before a bitter feud developed between them.

The impact on the electoral race is still far from clear, but the more evenly votes are split between Mr Soong and the vice-president, the better the chances of the opposition contender, Chen Suibian, whose pro-independence views would be anathema to China.