Attempts to form a new government in Lebanon failed even to begin on Monday as Hezbollah attempted to take advantage of the crisis.
A spokesman for the militant group said it was likely to nominate its own candidate for prime minister – a Syrian ally forced to step down from the job five years ago.
Omar Karami would step back into the role he gave up in the midst of the "Cedar Revolution" which forced a humiliating exit from Lebanon for Syria, one of Hezbollah's main backers.
Supporters of the current prime minister, Saad Hariri, whose cabinet fell last week when Hezbollah and its allies walked out, insist that he stay on.
Neighbouring countries, including Syria and Turkey, called for the resumption of talks between Mr Hariri's main international backer, Saudi Arabia, and Syria, whose failure last week prompted the Hezbollah move.
But with no sign of that happening, Michel Suleiman, the president, announced he was suspending attempts to appoint a new coalition for at least a week.
Hezbollah wants Mr Hariri to reject the findings of a United Nations special tribunal into the death of his father Rafiq, also a former prime minister, who was killed by a car bomb in February 2005.
The tribunal, which is due to hand over indictments imminently, is believed to have found evidence to prosecute Hezbollah members.
The murder was blamed on Syria at the time, leading to protests against the country's dominant position in Lebanese life, and the withdrawal of its army. Mr Karami stood down at the same time.
His return now would be a triumph for pro-Syrian elements in the country, even though they lost a general election last year.
Under a number of agreements ending the civil war and preventing a return to armed strife, the Lebanese cabinet has to represent all religious sects and political factions in Lebanon.