The Dewan Negara today passed the bill to amend the Federal Constitution to lower the voting age to 18.

The constitutional amendment was passed with a majority with 47 votes, just two more than the needed two-thirds support threshold of 45.

There were no abstentions or nays.

Dewan Negara president S Vigneswaran later revealed that a total 20 senators were absent from today's sitting.

"Congratulations to the ministers and all the senators (present)," added Vigneswaran.

This is the first time the Federal Constitution has been amended since the Abdullah Ahmad Badawi administration.

Besides lowering the voting age, the bill also permits automatic voter registration and the lowering of the minimum age for elected representatives to 18.

The bill was debated by 24 senators from both sides of the divide.

The bill was passed by the Lower House, the Dewan Rakyat, on July 16. 

At a press conference later, de facto law minister Liew Vui Keong said he regretted that 20 senators were absent from today's sitting.

"I regret that they did not attend because this is an important amendment and the attendance of all senators is compulsory and mandatory," he said.

"I will discuss with their chief whip and it's up to the chief whip to take action," he said.

Liew also said he expected the 18-year-old voters to be included in the electoral roll by next year together with the implementation of automatic voter registration.

The government still needs to amend three relevant laws and election regulations at the Parliament's next session in October, he added.