His blunt condemnation of gay marriage prompted Carl Katter to speak out, saying he did not understand his brother's motives nor his willingness to "target a minority and persecute them in the way he has. It's hurtful, it's dangerous, it's damaging ..."
Yesterday Carl Katter distributed a video appeal through the internet-based lgreg aobby group GetUp urging greater tolerance and a change in the laws banning same-sex marriage.
His nationwide appeal has given fresh impetus to what is already a growing campaign to legalise gay marriage.
MPs yesterday reported the views of their electorates to Parliament - raging from almost total opposition to overwhelming support - while gay marriage advocate Kerryn Phelps and other activists met Prime Minister Julia Gillard and Opposition leader Tony Abbott.
Both oppose same-sex marriage, although Gillard faces a mounting challenge from within the Labor Party.
Her gay Finance Minister, Penny Wong, will be a key advocate in a move to change Labor's policy at the party's national convention.
The Greens have introduced a bill to allow same-sex marriage to federal Parliament.
There is also support for same-sex marriage within the Liberals.