Emile Lahoud left the Baabda presidential palace in Beirut at midnight Friday, concluding a nine-year term as Lebanese president.
Hours before he steps down, Lahoud declared that threats of a state of emergency prevail over Lebanon and assigned the army to maintain law and order throughout the nation.
But Lahoud's decision was rejected by Prime Minister Fouad Seniora who said in a statement that the presidential measure is "not factual and not based on constitutional or legal authorities."
Earlier in the day, a parliamentary session to choose a successor to Lahoud was put off for a fifth time, creating a power vacuum of at least one week.
Under Lebanon's constitution, if no president is elected by the parliament in time limit, presidential powers pass to the government.
But Lahoud, an ally of the Hezbollah-led opposition, has reiterated that he would not hand over the power to the government led by Seniora, which he considered as "illegitimate."