Parliament Speaker Nabih Berri, a key opposition figure, locked out pro-government lawmakers from the chamber Tuesday, refusing to call the legislature into session to approve an international tribunal to try suspects in the assassination of a former prime minister. It was the third attempt in as many weeks by lawmakers from the anti-Syrian majority to try and force Berri to open the chamber's doors and call a session. Opposition legislators also came to the downtown building housing parliament to counter the gathering of the majority lawmakers, but the standoff ended peacefully. Tuesday's events have deepened both the paralysis in Parliament and the political crisis in Lebanon, which has since December been buffeted by an opposition campaign to bring down the Western-backed government of Prime Minister Fuad Saniora. Politicians from the anti-Syrian parliamentary majority have accused Syria of attempting to undermine the country's independence through its allies in Lebanon's opposition. They say Syria, which they blame for the 2005 assassination of former prime minister Rafik Hariri, aims to scuttle the formation of the court. Syria has denied involvement in Hariri's assassination in a truck bombing. The quarrel between the two sides has stirred political and sectarian tensions, threatening to tear the country apart. Nine people were killed in street clashes since December between pro- and anti-government supporters. The power struggle has paralyzed other branches of the government. President Emile Lahoud, a staunch pro-Syrian Christian, is boycotted by his prime minister and his allies in the anti-Syrian majority. Saniora also is in dispute with Berri. Berri and Lahoud consider the Cabinet unconstitutional after six pro-Hezbollah Cabinet ministers - all five Shi'ite Muslim representatives and a Christian - resigned in November. They argue that with the departure of all Shi'ite members, the Cabinet was unconstitutional because it breaches a Christian-Muslim power-sharing pact. Saniora, however, continues to enjoy international and Arab support.