Lebanon's acting Prime Minister Saad Al-Hariri on Monday ruled out joining a government led by a Hezbollah-appointed candidate, his office said, as consultations on nominating a new premier got underway.

"The (Hariri-led) Future Movement announces its refusal to participate in a government headed by a candidate named by the opposition," the statement said, referring to Shia militant group Hezbollah and its allies.

Hariri's statement came as former premier Najib Mikati was tipped as the favourite candidate to be appointed prime minister after he secured the backing of Iranian-backed Hezbollah, which brought down Hariri's government earlier this month.

Officials said Mikati, a telecoms tycoon, was Hezbollah's top choice given his position as a centrist politician who has good relations with the country's feuding parties.

Mikati, 55, submitted his candidacy on Sunday saying he was coming forward in the hope of being a consensual candidate.

But Hariri's Future Movement said there was no such thing as a "consensual candidate."

"There is a candidate named Saad Hariri, and then there is another candidate nominated by the opposition," the statement said. "Those are the only two choices."

President Michel Suleiman on Monday began two days of consultations with the country's 128 MPs, who will name their pick for premiership.