Lebanon's political crisis reached a new danger point on Saturday night when the cabinet approved the establishment of an international tribunal to investigate the assassination of former prime minister Rafik al-Hariri. The cabinet convened Saturday night, and after an initial delay, voted to cooperate with the UN-created court, despite warnings of mass protests by Hizbullah and the pro-Syrian camp. Pro-Syrian President Emile Lahoud has spoken out against the decision, claiming it was made by an "illegal government." Lahoud told outgoing UN Secretary General Kofi Annan and Prime Minister Fuad Saniora that he wouldn't accept the cabinet decision. Saniora insisted the approval of the tribunal was not meant as a "provocation" against Hizbullah and its allies, according to a statement read by Information Minister Ghazi Aridi after the vote. Aridi underlined the government's "respect" for Hizbullah's opinion, but insisted, "We will not give up our goals." For opponents of Syria, the court is a major priority, and they hope it will uncover the truth behind the February 2005 assassination of Hariri in a massive bomb blast that killed 22 others, which they accuse Damascus of orchestrating. Syria has denied any role in the killing. Hizbullah leader Sheikh Hassan Nasrallah and Parliament Speaker Nabil Berri issued a statement Friday evening renewing the threat of protests. They said they would use "all democratic and legal means" - a reference to peaceful demonstrations - to reach their goal of gaining a greater presence in the cabinet, one that would effectively give them veto power over government decisions. Earlier in the month, five Shi'ite ministers resigned from the government in protest against the anti-Syrian majority's refusal to give them more political representation. Security was tight in downtown Beirut amid reports that on Monday the country's Shi'ite population plans to stage mass street protests. Hizbullah has been threatening for weeks to mobilize its supporters to demand greater political representation. The movement now says its actions will include parliamentary resignations, strikes and sit-ins. The cabinet approval "now puts the opposition before its options to confront the government. The time and the place will be decided," said Sheikh Hassan Ezzeddine, a senior Hizbullah official, when asked if his organization would carry out its threatened protests. The international tribunal is a major source of contention between the Western-backed government of Saniora and the opposition led by Hizbullah. The government accuses Hizbullah of wanting to scupper the tribunal. Hizbullah denies this, claiming to support the court in principle. Tensions between the two groups were heightened by last Tuesday's assassination of Christian industry minister Pierre Gemayel. Many in Lebanon believe Syria had a hand in that assassination as well as in Hariri's death, but Damascus has rejected the allegations. On Friday Syria complained that it had not been consulted on the tribunal's plans for the tribunal and threatened not to cooperate with it. The court, which will sit outside Lebanon and have a majority of non-Lebanese judges, is to try four Lebanese generals - top pro-Syrian security chiefs under Lahoud including his presidential guard commander, who have been under arrest for 14 months, accused of involvement in Hariri's murder. The UN investigation into Hariri's death has also implicated Brig.-Gen. Assaf Shawkat, Syria's military intelligence chief and the brother-in-law of Syrian President Bashar Assad. But Shawkat is not in custody. AP contributed to this report.