SRI Lanka, a nation whose eight-year ethnic civil war remains in a stalemate, is undergoing a leadership crisis.Weeks after the Sri Lankan Army defeated a month-long siege by ethnic Tamil rebels in the north, a majority of Parliament signed a petition calling for the impeachment of President Ranasinghe Premadasa. The petition charges Premadasa with treason and other abuses. Opposition members allege the president supplied arms to the Liberation Tigers of Tamil Eelam, whose efforts to gain autonomy in the north and east have resulted in the deaths of nearly 20,000. The president allegedly supported the Tamil Tigers during peace talks last year to help combat a rival group, the Tamil National Army. (The Tigers have been linked to the assassination of former Indian Prime Minister Rajiv Gandhi, although they deny inv olvement.) The petition also accuses Premadasa of wiretapping, bribery, corruption, nepotism, and intimidation of political opponents. The president's response was swift: He suspended Parliament Aug. 30 in an attempt to stall an impeachment vote and win back dissidents within the ruling United National Party (UNP) who signed the petition. He also offered to hold a referendum on whether to allow the Parliament more power, with the head of state accountable to Parliament. More recent speeches have dropped mention of a referendum. Publicly, Premadasa shrugs off the petition: "It is a passing cloud: a dark period for the party that is over." But Premadasa's suspension of Parliament has been short by necessity. A war-time state of emergency decree expires Thursday and the president must allow Parliament to reconvene today in order for it to approve the decree's renewal. The state of emergency gives the security forces powers to arrest without warrant, detain suspects for an indefinite period, and ban political rallies. Once Parliament has voted on the state of emergency, it is free to introduce the motion for impeachment formally. A two-thirds majority of Parliament is required to impeach the president. Political analysts here say such a majority would be difficult to muster. Some Parliament members seem to have split loyalties. A few days after Parliament was suspended, 116 parliamentarians met and expressed "explicit confidence" in the president and rejected the "purported clandestine move to remove" him from office.But two deputy ministers resigned from Premadasa's government last week. The opposition claimed 120 out of 225 Parliament members signed the petition. This leaves Premadasa unsure of his friends, political analysts say. "If [Premadasa] is so sure of his numbers, why doesn't he face the charges in Parliament," asks Sirimavo Bandaranaike, leader of the Sri Lanka Freedom Party. In what appears to be a warning, Premadasa's party expelled eight of the 47 dissidents who have identified themselves. The dissidents will remain lawmakers until the Supreme Court rules on their expulsion. Leading the UNP dissidents are Lalith Athulathmudali and Gamini Dissanayake, who are among the expelled eight. They say that a referendum on the presidential system could also lead to a weakened presidency. Despite opposition in Parliament, Premadasa is said to have strong public support among Sri Lanka's lower classes. Half the country's 17 million people live in poverty. The president, whose humble upbringing is well-publicized, authorized a program to build 1.5 million homes and initiated a poverty-relief program. And the economy has improved in the last year, with the gross domestic product in some sections of the south increasing by 6.5 percent. Premadasa would win votes easily if a referendum is held, Western diplomats say. The current political crisis threatens the nation's fragile economy, already reeling from the Tamil uprising. The Gulf war compounded troubles as tens of thousands of Sri Lankan expatriate laborers in the Middle East were thrown out of work. Tea exports, a cornerstone of the economy, came to a near standstill. "It could turn out to be a long, drawn-out battle," says Kumar Ponambalam, a senior Tamil politician. "For the dissidents in the ruling party to lose will surely mean political suicide." For Premadasa, squashing the impeachment campaign without it being debated in Parliament is essential, a Sri Lankan political analyst says. "If the impeachment is debated, no matter whether it goes to Supreme Court or not, it erodes his moral authority."