Estonia's parliament has approved a law making it the first country to allow voting by mobile phone.

Lawmakers approved a measure last week allowing citizens to vote by mobile phone in the next parliamentary elections in 2011.

Estonians were allowed to cast internet ballots in last year's parliamentary vote.

The mobile-voting system, which has already been tested, requires that voters obtain free authorized chips for their phones, said Raul Kaidro, spokesman of the SK Certification Center, which issues personal ID cards in Estonia.

The chip will verify the voter's identity and authorize participation in the electronic voting system, he said.

The system and software have proven effective and reliable in an independent security audit, Kaidro said. He dismissed security concerns, claiming the system "is the most secure way to authenticate digital signatures."

Kaidro said he expects the 2011 vote to be the first of its kind, though he said neighbouring Finland and Sweden possess the software and technical capabilities to conduct a similar "cellular election."

Estonian officials said the internet voting system in 2007 proved secure despite worries about hacker attacks, identity fraud and vote count manipulation.