Zaid Ibrahim quit his posts and accused his colleagues of hypocrisy and fraud.

Former Law Minister Zaid Ibrahim's attack is certain to fuel a growing sense of dejection among opposition supporters tired of infighting and spark a political firestorm that could severely dent Anwar's public image as he battles sodomy charges.

Zaid — admired by many for being blunt about his political principles — announced he was resigning from several decision-making positions in the People's Justice Party and would no longer seek its No. 2 post because of signs "the leadership actively condones malpractices and electoral fraud to achieve its designed objectives."

Zaid, who was competing for the party post against a rival whom Anwar is known to favour, claimed there were irregularities in the distribution of ballot papers in the party's current elections for top office-bearers.

"I am certain that any political party with such hypocritical and false values will not be able to offer meaningful reforms to the people of this country," he said.

Zaid had once been considered a potential successor to Anwar if the opposition leader were to be convicted on charges of sodomizing a male former aide. Anwar denounces the charges, which could result in a 20-year prison term, as a government plot to block his political ascent. The government denies that.

Internal bickering in Anwar's three-party alliance has taken away much of the shine from major gains the opposition made in 2008 national polls and dampened opposition hopes of seizing federal power in elections that many expect to be held before mid-2012.