'My partner's illness brought everything into perspective.'

It’s been a decade since Christine Milne entered the Senate. Here, she writes exclusively for Debrief Daily about the very personal reasons that led to her decision to leave politics.

Many were shocked, that Wednesday morning in Canberra when I stepped down.

But all you really had to know was my age and that a Senate term is six years to realise it was a possibility. In order to lead the Australian Greens into the 2016 federal election I would have had to stand for re-election myself. I knew in my heart of hearts that I couldn’t, in all honesty, stand up before the people of Tasmania and ask for their support for another six years, when I had no intention of staying that long.

I will be 63 next year and I was in two minds.

Was I letting the sisterhood down by resigning as the only remaining female leader in the Federal Parliament? I rail against the discrimination older women face in public life, in the media and in business, and I think it's time to smash the stereotype that older men are "distinguished looking" wise elders, whereas older women are past it.

On the other hand, life as the leader of a federal political party is physically and mentally demanding, with constant travel, media performance pressure and high stress levels. It is unrealistic to think that you can keep it up indefinitely, and that your performance, health and wellbeing won't suffer.

Speculation was rife in those first few hours and days – why did I do it? Was I forced to go? Who knew what, when? Although hard, this decision was mine; the result of six months of soul searching. I was in the luxurious position of knowing that I had built a great team behind me who could do the job.

I regard leadership not as individual or ego driven, but as collective and enabling. My job as leader was to enable my team to achieve to their highest potential, to create the space for them to develop their skills, and they did. It’s the reason I was beaming with pride and confidence as I joined Richard Di Natale at our handover press conference: I knew that he, Larissa Waters and Scott Ludlam would do a great job leading the Australian Greens, and that the team would perform brilliantly. As I said on that day: They’re ready to fly, and I’m so excited to see all they’ll achieve.

In the same way I imagine it’s difficult to leave the small business you’ve worked to set up, or a building for which you’ve literally laid the foundations, it is hard to leave the parliamentary party which is as much a part of me as I am of it. I was there as an MP when the Tasmanian Greens and Australian Greens were formed. Walking out of the Senate for the last time last Thursday night was tough, because I’m passionate about our country, the world and the future of humanity and species, and there is so much still to be done. But there will always be more to be done and I reassure myself that political representation is only one avenue for addressing them.

As everyone in the Greens Party Room knows, I first considered the possibility of handing over last year when my partner Gary became seriously ill. His illness brought everything into perspective. Gary and I had consoled ourselves often, as we lived with my hectic lifestyle, that it would be different post-politics, but suddenly that opportunity looked lost.

Thankfully, Gary’s health is on the right track, and now my son James and his wife Shannon are about to have a baby – my first grandchild – and I so want to be a grandmother who is present, physically and emotionally.

With a new generation of our family on the way to love, teach, defend, learn from and be inspired by, I’m so determined to keep standing shoulder to shoulder with the community, here in Australia and all over the world, to fight for action on global warming. It’s still too soon to say exactly what form that will take, but I'll go to the UN climate talks in Paris at the end of the year and see what niche I can find to help achieve what the world needs: a safe climate.

As I said in my last speech, I am not leaving politics. I will be there as an activist and a feminist with purple stockings and more dangerous than ever.

For more from Christine try ...

Christine Milne’s farewell vow: ‘I’ll be more dangerous than ever.’

Christine Milne on why she’s never discussed her personal life until now.

Christine Milne resigns as the Leader of the Greens.