Comelec Chairman George Garcia said they rejected the request from the European Union (EU) to enter polling precincts on election day, 12 May.
According to the poll chief, allowing foreign observers inside polling precincts is a violation of Philippine law.
In a press conference, Garcia said the main purpose of this is to prevent them from doing any form of influence or disruption to the voting process.
He added that voters, electoral board members, the watchers of citizens' arms and political parties, and Comelec support staff are allowed inside polling centers and that even Comelec personnel cannot just enter.
He also acknowledged the consequences they may face for disallowing access, which could be seen as violating international standards, and said they are willing to face any of it.
Garcia further clarified that EU observers may still visit precincts and observe the voting procedures through windows outside the rooms.
The EU election observers submitted a formal letter to Comelec requesting permission from the electoral board to enter polling precincts and insisted that this is a crucial part of their job.