By Benet Koleka TIRANA, June 19 (Reuters) - Albanian members of parliament are due to start voting for a new president on Wednesday, but with no clear front-runner the outcome is far from certain and voting may even be postponed. Two of the most prominent candidates, former Socialist premier Fatos Nano and Bamir Topi, deputy chairman of the ruling Democratic Party, are still short of the support they need. The first round of voting by parliament for a successor to outgoing president Alfred Moisiu is on Wednesday. The winner will need a three-fifths majority. But for procedural reasons, voting may be postponed. Nano, one of the leading figures in Albanian politics since the fall of communism, says he is seeking the presidency because he has not served his country enough. Nano has been elected prime minister four times since 1991 but has only completed one full term. Asked by a talk show host on Monday about the longevity of other leftist premiers, such as Tony Blair of Britain, Nano said: "Me, I have served a mere 54 months in office." If there is no winner after five rounds, the constitution says Albania must hold a snap general election. Given its shaky election record, this could mean instability, distracting the country from its drive for European Union and NATO membership. Nano has publicly fallen out with his successor, the current Socialist Party leader Edi Rama. He is trying to convince Socialist colleagues to back him. but may have convinced only a dozen deputies so far. However, he may be in luck and end up emerging as the consensus candidate, bridging the gap between left and right. Nano, whose main function since losing the election in 2005 has been hosting visiting dignitaries in his opulent office, where coffee is served in cups marked 'N', said he remained convinced there would no need for an early general election. Topi, the other big name figure in a field of more than a dozen, has been hand-picked by Prime Minister and Democratic Party leader Sali Berisha, but is not popular in the party. Berisha's ruling coalition is under pressure to elect a president by consensus, as urged by the EU. Nano would be an unlikely choice for Berisha. The two men have been bitter rivals since 1991, accusing each other of corruption, incompetence and insanity at every opportunity. Diplomats say the EU and U.S. favour electing someone from the judiciary as president, and the names of high-ranking judges and former justice ministers have increasingly come up.