* U.S., UK try to convince lawmakers need for Syria strike
* No plan for new UN meeting on Syria - envoys
* UN chief Ban cuts short Europe visit due to Syria crisis (Adds end of meeting, diplomats saying no outcome)
By Louis Charbonneau and Michelle Nichols
UNITED NATIONS, Aug 29 (Reuters) - The five permanent U.N. Security Council members met again on Thursday to discuss an alleged chemical weapons attack in Syria last week as Western powers consider possible military action against the Syrian government, U.N. diplomats said.
The meeting lasted for just under an hour. U.S., British, French, Chinese and Russian diplomats declined to comment to reporters after the meeting. One diplomat said it was not clear why Russia had called for the meeting and nothing new was raised.
"There's no further P5 (permanent council members) meeting scheduled but that could change," a diplomat told Reuters on condition of anonymity. Russian diplomats declined to comment on the meeting apart from the fact that it had ended.
Britain, China, France, Russia and the United States held an inconclusive meeting on Wednesday on a draft Security Council resolution that would authorize "all necessary force" in response to the alleged gas attack.
The five permanent members have veto powers on the Security Council. Russia, Syria's main arms supplier, as well as China, have already vetoed three resolutions condemning Syrian President Bashar al-Assad's government and threatening it with U.N. sanctions.
Russia has made clear it opposes any military action in Syria and suggested the rebels may have launched last week's attack that killed hundreds of people in suburbs east of Damascus. Syria has also blamed the rebels and urged Ban to investigate reports of rebel gas attacks.
So far, Britain has not submitted its draft resolution to the full 15-nation Security Council. Diplomats told Reuters that it was not clear if a resolution would be put to a vote in the council given that Russia would almost certainly veto anything authorizing the use of force against Syria.
The U.N. meeting came as President Barack Obama and British Prime Minister David Cameron sought to convince cautious lawmakers and the public of the need to strike Syria, though U.S. officials conceded they lacked conclusive evidence that Assad ordered his forces to use chemical weapons against civilians.
The United Nations has received at least 14 reports of possible chemical weapons use in Syria. After months of diplomatic wrangling, a team of experts, led by Swedish scientist Ake Sellstrom, arrived in Syria on Aug. 18.
The U.N. team was initially going to look into three incidents, but its priority became investigating an alleged gas attack in the rebel-held suburbs of Damascus last week, which activists say killed hundreds of civilians.
"The team was able to do some preliminary work about the three sites it was initially looking into but it has not been able to conduct onsite visits ... basically because this new priority rose up while they were in country," U.N. spokesman Farhan Haq told reporters.
"The Secretary-General does expect to have some form of an oral briefing from the investigators once they are out of the country," Haq said. "The investigators as currently scheduled expect to wrap up their work by Saturday morning."
He said Ban was returning to New York on Thursday after cutting short a trip to Europe.
Germany and France have called for an immediate briefing for the Security Council on the investigation team's results as soon as they become available. They also called for an international reaction to last week's alleged gas attack in Syria. (Reporting by Louis Charbonneau and Michelle Nichols; editing by Jackie Frank and Cynthia Osterman)