Same-sex marriage supporters rally in Melbourne. Credit:David Crosling Supporters of same sex marriage say they are concerned about the bigotry and intolerance that will be whipped up by the plebiscite now going ahead. So far, it's the supporters of change, not the opponents, who've been responsible for bullying and hate speech. The Archbishop of Hobart has been dragged before a tribunal for defending Christian teaching. Coopers Brewery was bullied into withdrawing support for the Bible Society after sponsoring a debate about marriage. A Father's Day ad was banned for being "political". There's been fake news about non-existent homophobic posters and a homophobic ram raid that never happened. "Love might be love" but it's striking how little love the supporters of same sex marriage are showing for anyone who disagrees with them. It's paradoxical how respect has flown out the window in the fight for yet more respect. It's hard to see, at least from the tenor of the campaign to bring it in, how we would be a more decent society with same sex marriage than without it. At one level, the same sex marriage debate is of vastly less relevance than most people's daily struggle to pay their bills, to improve their lives and that of their families, and to try to get on with their neighbours and workmates. But at another level, almost nothing is more important than the values that we cherish and the principles on which our society is based.

In the US, a baker has been prosecuted for refusing to put a slogan on a wedding cake. Credit:AFP We shouldn't lightly change what's been the foundation of our society for generations; and, if we do, it should only be after the most careful weighing of all the consequences. Yet if the polls are to be believed, we are about to discard the concept of marriage that has stood since time immemorial in favour of a new concept that would have been scornfully rejected even by gay people just a generation ago. This week, an anti-same sex marriage gay activist posed the question: "How are women going to recognise lesbianism as an alternative to heterosexuality if they don't see us protesting against institutions that have been harmful to us: like marriage, prostitution and the nuclear family?" I'm sure that some gay activists really believe that they are trying to promote stable, long-term relationships by extending marriage to same sex couples; but others clearly want to subvert marriage. And the gay people demanding to be married don't want their relationships to change; they just want them to be accorded a new status. It's said that there should be absolutely no difference, even in terminology, between relationships because "love is love". Yet there are many different types of love. No one is saying that one type of loving relationship is better than another, just that they can be different. By all means, let's find a way to solemnise what is intended to be a sacrificial love between two people of the same sex; but it remains a different love even though it's not a lesser one.

At one level, insisting upon any particular definition of marriage may seem like pedantry. At another level, though, it's important to maintain cultural and intellectual integrity. A man is not a woman just because he wants to be, and a same sex relationship should not be able to become a marriage just because activists demand it. All the overseas evidence shows that allowing "any two persons" to marry brings many other changes in its wake. In Britain, Catholic adoption agencies have been forced to close down and an orthodox Jewish school threatened with defunding. In America, a baker has been prosecuted for refusing to put a slogan on a wedding cake. This week in Quarterly Essay, a "safe schools" supporter, Benjamin Law, said that "it might be stating the obvious but same sex marriage is far from the final frontier in the battle against homophobia" – prompting the equally obvious question: how can parents keep gender fluidity programmes out of schools here in Australia when gender fluidity has entered the Marriage Act? If the advocates for same sex marriage can't demonstrate how freedom of speech, freedom of religion and parental choice will be protected in their brave new world, they're asking voters to sign a blank cheque. Australians have never liked being pushed around or hoodwinked. When big businesses from Uber, to Subway, to the makers of Magnum ice cream are virtue signalling on same sex marriage, it's time to say that political correctness has got completely out of hand and to vote "no" to stop it in its tracks. Loading

Tony Abbott is the federal member for Warringah and a former Australian prime minister. An earlier version of this story said a doctor who went public with her concerns about the consequences of same sex marriage copped a GetUp! petition to have her struck off. This is incorrect. GetUp! did not support the petition, endorse or organise it.