Malaysia’s government was rocked by a minister’s resignation Monday in a storm of criticism over a series of arrests under new security laws just as it faces an opposition plot to seize power.

The furore highlighted the disarray within the Barisan Nasional coalition, which has been rattled by opposition leader Anwar Ibrahim’s much-touted plans to form a new administration with the help of defecting lawmakers.

Anwar has set a Tuesday deadline to topple the coalition, but said over the weekend that although he has enough support for a takeover, its timing could be delayed in order to preserve national stability.

Cabinet minister Zaid Ibrahim, who is in charge of legal affairs, resigned after leading criticism of Saturday’s arrests of an opposition politician, the nation’s leading blogger, and a reporter for a Chinese-language daily.

Zaid said the government was wrong to use the Internal Security Act (ISA), which allows indefinite detention without trial, and tendered his resignation to Prime Minister Abdullah Ahmad Badawi, according to his aide.

“The ISA is open to abuse. If we cannot be fair in implementing it, then we should confine its use to terrorists,” Zaid said according to the New Straits Times. AFP

The maverick ruling-party member was appointed to the cabinet in a March reshuffle and charged with cleaning up Malaysia’s much-criticised judiciary, but since then the coalition’s reform agenda has withered.

“I joined the government because I believe there would be transformation. The government must change but reform cannot take place if it continues with the old thinking and old philosophies,” Zaid reportedly said.

The ISA arrests triggered fears that the government was planning a wider crackdown on dissent to crush Anwar’s ambitions, but the quick release of the journalist on Sunday eased fears of a national crisis.

Home Minister Syed Hamid Albar defended the detentions but said it was a police operation and not his idea — comments ridiculed by the opposition which said he and Prime Minister Abdullah Ahmad Badawi were accountable.

Abdullah must explain whether the crackdown was rolled out “in order to protect his position as prime minister now that he is under attack,” opposition veteran Lim Kit Siang told a press conference.

Lim said it appeared deputy premier Najib Razak and Trade Minister Muhyiddin Yassin were “teaming up” to challenge Abdullah, who has faced repeated calls to quit since a drubbing in March general elections.

Abdullah had announced a plan to hand over to Najib in mid-2010 but both the deputy premier and trade minister have drawn question marks over the plan.

In a rare eruption of dissent, six ministers criticised the ISA arrests, with Information Minister Ahmad Shabery Cheek welcoming the release of the journalist, who had reported racist remarks made by a ruling party lawmaker.

Opposition lawmaker Teresa Kok, from the Chinese-based Democratic Action Party which is a member of the opposition alliance, was also arrested over allegations she complained about the noise of morning prayers at a mosque.

She has said the accusation was “preposterous”.

The other detainee is Malaysia’s leading blogger, 58-year-old Raja Petra Kamaruddin, who has repeatedly targeted government figures on his website “Malaysia Today”.

He has already been charged with sedition and defamation after linking Najib and his wife to the sensational murder of a Mongolian woman.

Anwar, a former deputy premier who was sacked and jailed a decade ago, will later Monday address a mass rally at a Kuala Lumpur stadium, at which he is expected to elaborate on his plans to take power.