Former prime minister reveals grief, pain and regret over losing power, and issues fierce defence of her time in office in article for Guardian Australia

Julia Gillard has talked for the first time about the deep pain and grief she felt about losing power, and how she chose to spend the night of the federal election alone.

In an exclusive 5000-word article written for Guardian Australia, the former Labor prime minister of Australia says that “losing power is felt physically, emotionally, in waves of sensation” and that the pain “hits you like a fist, pain so strong you feel it in your guts, your nerve endings.”

Gillard also says that Labor lost the election because Kevin Rudd returned without “one truly original new idea” and because he was unable to explain her enduring policy achievements. She believes that the party could muster no reason for his comeback other than that its polling might improve.

The wide-ranging article is the first time Gillard has made any comment about her removal as prime minister of Australia in June.

In an unusually frank description of the emotional impact of losing power, Gillard writes: "I sat alone on election night as the results came in. I wanted it that way. I wanted to just let myself be swept up in it."

She continues: "Losing power is felt physically, emotionally, in waves of sensation, in moments of acute distress. I know now that there are the odd moments of relief as the stress ekes away and the hard weight that felt like it was sitting uncomfortably between your shoulder blades slips off. It actually takes you some time to work out what your neck and shoulders are supposed to feel like.

“I know too that you can feel you are fine but then suddenly someone’s words of comfort, or finding a memento at the back of the cupboard as you pack up, or even cracking jokes about old times, can bring forth a pain that hits you like a fist, pain so strong you feel it in your guts, your nerve endings.

“I know that late at night or at quiet moments in the day feelings of regret, memories that make you shine with pride, a sense of being unfulfilled can overwhelm you. Hours slip by."

The article also includes:

a fierce defence of Labor's policy contributions;

an appeal to the Labor party to choose future leaders on the basis of substance and purpose rather than opinion polls;

an admission of mistakes Gillard says she made over the carbon tax, including not contesting the label that it was a “tax” for fear that the media would play “silly word games” and try for a “gotcha” moment; and also a plea to Labor to stand firm on its policy on carbon pricing: “climate change is real”;

praise for Rudd as “right and brave” for sticking with Labor’s policy on carbon pricing in the election, as well as an attack on some of his “bizarre” policy ideas.

On Rudd’s ousting of her in June 2013, Gillard is withering.

"Labor comes to opposition having sent the Australian community a very cynical and shallow message about its sense of purpose," she writes.

Labor’s decision to change leader was “only done - indeed expressly done - on the basis that Labor might do better at the election. Labor unambiguously sent a very clear message that it cared about nothing other than the prospects of survival of its members of parliament at the polls.”

She continues: “No alternate purpose was articulated during the election campaign that made sense to the Australian people. Kevin clearly felt constrained in running on those policies where Labor had won the national conversation, because those policies were associated with me. Yet there was not one truly original new idea to substitute as the lifeblood of the campaign.”

Gillard urges her Labor colleagues to own major policies which she argues have so dominated the debate that the Coalition has been forced to accept them — including on disability reform, school funding and education more broadly.

And, contrary to suggestions by some in Labor that the party should agree to the repeal of the carbon tax, Gillard is adamant that Labor must also stand firm and stick with its policy on carbon pricing, even though "without doubt, Tony Abbott won this public opinion war and dominated this political conversation.”

"Labor should not in opposition abandon our carbon pricing scheme,” she insists. “Climate change is real. Carbon should be priced. Community concern about carbon pricing did abate after its introduction. Tony Abbott does not have a viable alternative.

“While it will be uncomfortable in the short term to be seen to be denying the mandate of the people, the higher cost would be appearing as, indeed becoming, a party unable to defend its own policy and legislation: a party without belief, fortitude or purpose."

She acknowledges she "erred by not contesting the label ‘tax’ for the fixed price period of the emissions trading scheme", a decision that paved the way for Tony Abbott's contention that she had broken her pre-election promise not to introduce a carbon tax.

"I feared the media would end up playing constant silly word games with me, trying to get me to say the word 'tax'. I wanted to be on the substance of the policy, not playing 'gotcha'. But I made the wrong choice and, politically, it hurt me terribly."

She also attributes blame for Labor's earlier political failures on climate policy to Rudd, for failing to "embrace Malcolm Turnbull’s bipartisanship when it was on offer", and then failing to "go to an election early on carbon pricing in late 2009 or early 2010." But she praises him for sticking with the policy in 2013.

"Labor is on the right side of history on carbon pricing and must hold its course. Kevin Rudd was both right and brave to say this in the dying days of the campaign," she says.

However she ridicules several of Rudd's 2013 policy ideas, which she calls on the party to ditch immediately. "The bizarre flirtation in the campaign with ‘economic nationalism’ and the cheap populism of appearing anti-foreign investment must be chucked out now. Poor policies like the different corporate tax rate for the Northern Territory and the hugely expensive move of naval assets from Garden Island should be ditched."

The former prime minister connects her own grief at her defeat to that which her colleagues are feeling now because they were voted out of government, or lost their seats.

"I know that my colleagues are feeling all this now. Those who lost, those who remain. We have some grieving to do together."

But she exhorts the Labor party, to which she devoted most of her adult life, to remain focused and positive.

"Ultimately it has to be grieving for the biggest thing lost, the power to change our nation for the better. To protect those who need us to shield them. To empower through opportunity. To decide what future we want for all our nation’s children and then build it. And when the grieving is done, that’s our purpose."