In a sarcastic swipe, Gerakan Youth chief Tan Keng Liang has questioned if all "murderers, rapists and sodomites" should be freed from prison in order for them to vote in an election.

Referring to PKR, Tan tweeted: "They now want the prison to release Anwar (Ibrahim) and allow him vote in Permatang Pauh."

"What about other murderers, rapists, sodomites, etc? Free them too?" he added.

Tan also uploaded an image showing Article 119(3)(a) of the Federal Constitution, which states a convict is disqualified as a voter.

Anwar's legal team is considering taking action against Election Commission (EC) chairperson Abdul Aziz Mohd Yusof if the former opposition leader is barred from voting in the Permatang Pauh by-election.

In a legal demand sent to Aziz earlier today, the lawyers said Anwar had registered to vote before he was imprisoned and the EC's refusal was a "breach of law".

Previously, Home Minister Ahmad Zahid Hamidi said , based on the EC law, persons of unsound mind and prisoners cannot vote.

'Convicts should join Pakatan'

Meanwhile, Tan called on "murderers, rapists and sodomites" to consider joining Pakatan Rakyat.

"(Following this) Get your spouse to contest (in the) election. Your only hope to be freed," he tweeted.

This was an obvious reference to PKR president Dr Wan Azizah Wan Ismail, who is contesting in the Permatang Pauh by-election.

The seat fell vacant following her husband Anwar’s conviction and incarceration for sodomy.

Tan also pointed out that Anwar attempted to seek a royal pardon.

"Would an innocent person do that?" he asked.

On Feb 10, the Federal Court upheld the former opposition leader’s conviction and five-year prison sentence.

Anwar has always maintained that the charge against him was fabricated by his political rivals, but the government has denied this.