One of the most influential members of the U.S-backed ruling coalition, which was dealt a military blow by Hezbollah in six days of fighting, called for concessions to avoid more conflict.
"Let us deal with matters calmly at the dialogue table. Each one of us and them must offer concessions to bury strife," Walid Jumblatt said during a tour of Druze villages where his followers this week battled the Iranian-backed Shi'ite group Hezbollah.
"We are going to the dialogue with a great political wound," said Jumblatt, who was expected to leave for Qatar later on Friday.
Arab mediators, led by the Qatari prime minister, concluded a deal on Thursday to end the fighting which killed 81 people and exacerbated sectarian tensions between Shi'ites loyal to Hezbollah and Druze and Sunni followers of the ruling coalition.
Qatar invited the rivals to Doha for talks to end a broader political standoff that has paralysed government for 18 months and left Lebanon without a president since November.
The talks in Doha are not likely to start before Saturday, political sources said. Syria, which backs the opposition and is an ally of Iran, said it supported the Qatari-led Arab League initiative.
"This step could be a real chance to save Lebanon from the dangers that threaten it," Syria's Foreign Minister Walid al-Moualem told the Lebanese as-Safir newspaper. "We are absolutely with the initiative."
Washington holds Syria and Iran to blame for Hezbollah's campaign against the ruling coalition, which is also backed by Saudi Arabia. The military action forced the government to rescind two decisions which had triggered the escalation.
Hezbollah, a political group with a powerful guerrilla army, had seen the government move to ban its communications network as a declaration of war.
In another concession to the opposition, the ruling coalition also appears to have dropped its demands that the election of a new president precede discussions on a new cabinet and a new parliamentary election law -- the two main issues on the agenda of the Qatar talks.
"The atmosphere is excellent and we will put our efforts into reaching a solution which is in the interest of all Lebanese," Parliament speaker Nabih Berri, an opposition leader allied to Syria, told as-Safir.
The opposition has demanded more say in a cabinet controlled by factions opposed to Syrian influence in Lebanon.
The anti-Damascus factions have long accused the opposition of seeking to restore Syrian domination that was brought to an end in 2005. International pressure that year forced Syria to withdraw troops from the country after the assassination of former Prime Minister Rafik al-Hariri.
The ruling coalition's refusal to yield to the opposition's demand for veto power in cabinet triggered the resignation of all its Shi'ite ministers in November 2006. Lebanon was plunged into its worst political crisis since the civil war.
A deal would lead to the election of army commander General Michel Suleiman as president. Both sides have long accepted his nomination for a post reserved for a Maronite Christian in Lebanon's sectarian power-sharing system.
Under a deal, the opposition would also remove a protest encampment that has closed off central Beirut since December,