Lebanese politicians on Monday cast doubt on whether MPs would gather the following day to elect the country's army chief as president because of continued wrangling between rival parties.Barring a last-minute deal, Tuesday's parliamentary session could be postponed for a few days, or even until early next year, several officials said. It would be the eighth time the vote has been postponed for lack of agreement between the Western-backed majority and the Hezbollah-led opposition on who should succeed Emile Lahoud, whose term ended on November 23.