How things have changed. Less than three years later it is widely speculated that a similar bill would pass if (and it’s a big if at this point) all MPs are allowed a free vote. It goes without saying that I welcome the latest private member’s bill from Warren Entsch and Teresa Gambaro, which has been seconded by Terri Butler and co-sponsored by Laurie Ferguson, Adam Bandt, Andrew Wilkie and Cathy McGowan.

But I read with some dismay Senator Eric Abetz’s dismissal of marriage equality as a non-issue that didn’t matter to many people in the community.

I think that he is wrong.

People across Australia want marriage equality to happen. It may not be everyone’s number one priority, but it is wrong to argue that it is just an indulgent hobby of the inner-city “latte left”. The numbers don’t lie; a clear majority of people think it is time that we changed the definition of marriage. Galaxy figures tell us that 64 per cent of Australians support marriage equality, including a majority of people who identify as Christian.

But there is something else that Senator Abetz refuses to recognise – the importance of marriage equality to LGBTI people who actually want the right to marry. They don’t seem to figure at all in the thinking of some opponents to marriage equality.

What Senator Abetz doesn’t seem to understand is that marriage equality isn’t just about affording a new privilege to same-sex couples. It is about removing discrimination, something which impacts on the lives of LGBTI people every day.

We have known for some time that LGBTI people suffer from higher rates of mental illness than the rest of the population. In fact, their mental health is amongst the poorest in Australia and a National LGBTI 2013 Briefing Paper on mental health and suicide pointed to research which shows just how dire the situation is. Lesbian, gay and bisexual Australians are twice as likely to have a high or very high level of psychological distress as their heterosexual peers. Same-sex people have up to fourteen times higher rates of suicide attempts than heterosexual people and up to 50 per cent of transgender people have actually attempted suicide at least once in their lives. Across the LGBTI community the average age of a first suicide attempt is sixteen years of age.

But can marriage equality play a role in improving the wellbeing of LGBTI people? There is strong evidence that it can.

In 2012 the National Drug and Alcohol Research Centre’s Drug Policy Modelling Program investigated whether marriage equality could actually prove an effective public health strategy. Their findings concluded that reducing the stigma and discrimination that LGBTI people experience has a measurable and consistent impact on specific health indicators.

The Drug Policy Modelling Program didn’t rely on abstract ideas to make this argument. Research from the United States has examined the ramifications of individual states introducing legislative amendments to limit the definition of marriage to be between a man and woman. These states saw significant increases in alcohol use disorders among homosexual people. The results were controlled for time effects and there were no corresponding increases in those states without such an amendment. It is corroborated by research which found that recognition of relationship status actually moderates stress in LGBTI populations and that there are profound differences between legal and social recognition.

The meaning behind all of this is clear – reducing discrimination against LGBTI people has a definitive public health impact and marriage equality is a key part of this. Achieving marriage equality is more than just demonstrating a symbolic show of support for the LGBTI community. In fact, some researchers have stated that marriage equality can be regarded as sound public health policy. Perhaps some MPs wavering on whether to support changing the definition of marriage should consider that it really matters to same-sex people and can impact on their wellbeing and sense of worth.

Marriage equality should not be considered a distraction or a niche interest. It is an issue of discrimination and the wellbeing of people who actually identify as LBGTI should be front and centre of this debate.