BEIRUT, Lebanon - Lebanon's President Emile Lahoud declined on Saturday to endorse a draft accord sent to him by the Cabinet seeking to create a tribunal to try suspects in the killing of a former premier.

Lahoud, a staunch ally of Syria, said the Cabinet that approved it has lost its constitutional legitimacy.

The president had been expected to decline endorsing the agreement, sent to him Nov. 27. The accord would set up the U.N.-backed court to try the suspected assassins of former Prime Minister Rafik Hariri, who died in a massive truck bombing in February 2005.

Lahoud, in a statement issued by his office, said he was returning the draft accord to Cabinet "for reviewing as soon as a constitutional and legitimate Cabinet is formed."

The president considers the government of U.S.-backed Prime Minister Fuad Saniora to be unconstitutional since six pro-Syrian Cabinet ministers, including all the Shiite Muslims, resigned last month shortly before the government initially approved the tribunal.

The move caused Lahoud, a Shiite, to say the government should step down because the constitution requires all sects to be represented in the Cabinet. But Saniora, who also is backed by anti-Syrian factions, has refused to resign, saying the Cabinet meetings still had the quorum necessary to make decisions, including the approval of the tribunal.

The tribunal has become the latest weapon in the battle between the Hezbollah-aligned pro-Syrian factions and the anti-Syrian parties over the demand by Hezbollah for a third of the Cabinet's seats. Securing one-third of the seats would give Hezbollah and its supporters veto power over key decisions, including the U.N. document setting up the tribunal.

The creation of the tribunal not only requires Cabinet's approval but also Lahoud's and the Lebanese Parliament's endorsement. But the U.N. Security Council also could also bypass Lebanon and approve the tribunal on its own.

Saniora's Cabinet is now expected to refer the accord to the Parliament for approval even without Lahoud's signature. But Parliament Speaker, Nabih Berri, a a Hezbollah ally, supports the view that the Cabinet is no longer constitutional and has signaled he will not convene parliament to endorse the document.

The Syrian-backed Hezbollah guerrilla group and its allies in the opposition began open-ended street protests, now in their ninth day, to bring down Saniora's government after talks on forming a national unity government failed. The groups have called for a huge demonstration Sunday, saying it will mark an escalation in their attempts to oust Saniora's government.

The political crisis has taken dangerous sectarian lines, with most Sunni Muslims supporting the Sunni prime minister and Shiites backing Hezbollah. Christian factions are split between the two camps. -AP