Kathmandu - Nepal's constituent assembly on Monday started voting in a run-off election to choose the country's first president. 

Voting began at 8 am (0215 GMT) with members queuing up to cast their ballot in a two-way contest between Maoist-backed Ramraja Prasad Singh and Nepali Congress candidate Ram Baran Yadav. 

Nepalese media predictions gave Yadav a slight edge in the voting. 

The election has split the two-and-a-half-year ruling alliance with the Maoists threatening to stay in opposition if their candidate loses. 

While the Maoists emerged as the biggest party in April's constituent assembly election, but with 220 seats, are well shot of a majority. 

Both the Nepali Congress and the Maoists were trying to secure the support of fringe parties that could make a significant impact on the results. 

"We are hopeful that our candidate will get a majority as we have been assured support by parties who did not support our candidate in the first round of voting," said Prakash Man Singh, vice president of the Nepali Congress. 

"We are still hopeful of consensus with the Maoists on formation of the government," Prakash Man Singh said. 

The run-off became necessary because no candidate secured a majority of the registered 598 assembly members necessary for an outright win in Saturday's first round of voting. 

An official statement by the assembly said Yadav received 283 votes, 15 short of the 298 necessary. Maoist-backed Singh received 270 votes. 

The Maoist Singh 23 years ago led a brief armed uprising against Nepal's monarchy, carrying out bomb attacks in several locations in Kathmandu, including the royal palace. 

He was sentenced to death in absentia by a court but was never captured and lived in exile in India. 

Yadav is the Nepali Congress' general secretary and has been at the forefront of the party's struggle for democracy. 

The election marks part of Nepal's moves toward peace after the end of a Maoist insurgency nearly two and half years ago. 

The assembly already elected Parmanand Jha of the Madhesi People's Rights Forum as the first vice president of the country. (dpa)