The Veronicas have made an impassioned plea for Australia’s political leaders to embrace equal rights for same-sex marriage.

The sisters Lisa and Jessica Origliasso have published an open-letter to the country’s prime minister Tony Abbott which they’ve read aloud for a video published on their Facebook page.

With their campaign clip, the twins have not only thrust themselves into a hot-button topic Down Under, but in doing so they’ve fired a broadside at the nation’s maligned rightwing leader.

The Veronicas Perform 'You Ruin Me'

“Mr Abbott,” said Lisa, ”you've missed the opportunity to become a revolutionary leader on this matter and it’s time now to align with the growing number of governments who have paved the way for us and not continue our alignment with governments who persist in restricting equal human rights and social progression for its people and country."

She continued, “Tradition founded upon laws of discrimination and prejudice does not deserve sanctity in the name of history.”

The Veronicas spoke at the Marriage Equality rally in their hometown, Brisbane on the weekend and they’ve been long, loud supporters of equal rights for LBGTQI communities.

The pair explained they’d just arrived back from the U.S. where the Supreme Court in June ruled that gay marriage bans are unconstitutional, effectively legalizing gay marriage across all 50 states (Ireland also legalized gay marriage after the majority of the country voted "yes" in a referendum). “The example set by government is so powerful and so influential, and that’s why we’re here today,” they said.

The Veronicas Sign Global Deal With Sony Music, New Album Coming

The Veronicas’ message is a timely one. The Marriage Equality Bill is expected on Tuesday to go to Parliament's selection committee, which will decide on whether the bill can be introduced to parliament next Monday.

Added Jessica, “We believe in celebrating a diverse Australia. We also believe as humans we are all inherently connected and that our similarities far outweigh our differences. We all experience love. We all experience fear. We all bleed the same way.”

Before signing out, Jessica warned, “The legal and institutional framework that governs Australia must treat all people equally and we will not stay quiet until we have reached Full Equality for all!"

“Prime minister,” concluded Lisa, “why delay for another moment the chance to create a more compassionate, more harmonious and equal Australia?”

The Veronicas' self-titled third album (its first through Sony Music) debuted at No. 2 on the ARIA Albums Chart in January. The lead single "You Ruin Me" went one better when it peaked at No. 1 on the ARIA Singles Chart and cracked the U.K. top 10. The duo's biggest hit in the U.S. to-date has been "Untouched," which reached No. 21 on the Billboard Hot 100 in 2009.