MANILA, Philippines – (UPDATE) Western election observers on Saturday criticized the Philippine government for "insufficient" openness as the country prepares to choose its next president with a new automated voting system.

While it recognized that "substantial efforts" were being made to improve on previous elections, the US-based National Democratic Institute mission still urged the state poll watchdog Commission on Elections (Comelec) to do more to ensure that machines are fraud-proof and have adequate backup.

The Philippines, for the first time, will use the machines to count ballots and pool and transmit results from more than 350,000 precincts.

"The perception, whether fair or not, is that the Comelec has not done so. When it concerns elections, perceptions can be as important as reality," it said after it concluded a weeklong visit in the country.

This perception has "inhibited public confidence in the elections and generated anxiety about the automated election system, " it added.

Fifty million voters are set to go to the polls on May 10, when 17,000 posts from president down to municipal council seats will be contested.

The report said the Comelec has yet to reveal to candidates and voters what backup plan they have in place in the event the automated system fails.

"The biggest challenge and contribution that the Comelec can make is to communicate openly and frankly," Thomas Barry, NDI's deputy regional director for Asia, told a news conference.