And in a forthright speech to the group at Canberra's Hyatt Hotel, Mr Shorten will say that he has spent his working life trying to show empathy and compassion and "answer the Christian call to care for the vulnerable, to speak up for the voiceless, to reject hatred and intolerance, to help the poor and to pursue peace". Acting director of Australian Marriage Equality Ivan Hinton-Teoh (left) and Mikael Svensson, general manager of the Hyatt Hotel, Canberra. Credit:Jamila Toderas No faith has a monopoly on compassion, Mr Shorten says, and no religion "owns" tolerance or charity or love according to extracts from the speech. "Australia is full of decent and generous people of good conscience, drawn from all faiths and none. And no faith, no religion, no set of beliefs should ever be used as an instrument of division or exclusion." "So when I hear people invoking the scriptures to attack blended families. I cannot stay silent. I do not agree. When I see people hiding behind the bible to insult and demonise people based on their sexuality I cannot stay silent. I do not agree."

"When I hear people allege that 'God tells them' that marriage equality is the first step on the road to polygamy and bigamy and bestiality, I cannot stay silent. I do not agree." Mr Shorten, who is in a "blended" family with wife Chloe and their children, will say that these prejudices do not reflect the Christian values he believes in but concedes "I know some of my policy ideas will not win acceptance with the Australian Christian Lobby". Appearances before the ACL have become something of a political rite of passage in recent years. In 2012, Mr Shorten voted in support of same-sex marriage in a parliamentary vote that was defeated. The ACL opposes same-sex marriage and the views of its former managing director turned deputy chairman of the board, Jim Wallace, have attracted severe criticism.

On Anzac Day, 2011, he tweeted "Just hope that as we remember servicemen and women today we remember the Australia they fought for – wasn't gay marriage and Islamic!" Labor MP Shayne Neumann, who will speak at the conference about the importance of constitutional recognition for indigenous Australians, praised Mr Shorten for confronting the issue. "That's Bill for you," he said, adding it was good for political leaders to "speak to organisations around the country of a variety of different political hues, values and positions". The Hyatt Hotel has come under fire for hosting the ACL conference. The hotel chain said it supports gay and lesbian equality and will host rival events for supporters and opponents of same-sex marriage. While the ACL conference has been planned for some time, on Friday it emerged that a new gay and lesbian community group called the Australian People's Lobby Party and Canberra's GayCrash will both invite members to events at the hotel as the conference gets under way.

with Tom McIlroy and Emma Kelly