In his final interview, the author reflected on politics, the financial crash – and the death of the former prime minister

In the last interview he gave before his death, the author Iain Banks admitted feeling "half a second" of elation when he learned that Margaret Thatcher had died.

Banks's humour, enthusiasm for life and work and his political rage were all undimmed when he spoke to Stuart Kelly for the Guardian just a few weeks before his death from cancer on Sunday, aged 59.

He learned of Thatcher's death – which would have kept his own news off the front pages had it been the same day, he mused – on his honeymoon after inviting his partner, Adele Hartley, "to do me the honour of becoming my widow".

"Then I realised I was celebrating the death of a human being, no matter how vile she was. And there was nothing symbolic about her death, because her baleful influence on British politics remains undiminished. Squeeze practically any Tory, any Blairite, and any Lib Dem of the Orange Book persuasion, and it's the same poisonous Thatcherite pus that comes oozing out of all of them."

The coalition government, New Labour and Ukip were equally lambasted. He said: "My injured self respect can at least fall back on the fact that I never voted for New Labour – Labour yes, and nothing but Labour for as long as it existed and I could vote, but not for a party that embraced privatisation and refused to scrap nuclear weapons; not for a party slightly to the right of Ted Heath's government."

Banks said he would miss voting yes in the referendum on independence for his native Scotland – which he predicted will fail.

"I was saying last year that if we don't get it in 2014 we'll get it in my lifetime, and now it turns out that my lifetime might not extend as far as the first referendum, and that just seems so wrong – a Scotland still shackled to a rightwing England, especially with the rise of the bizarrely named Ukip.

"I wont miss waiting for the next financial disaster because we still haven't dealt with the underlying causes of the last one. Nor will I be disappointed not to experience the results of the proto-fascism that's rearing its grisly head right now. It's the utter idiocy, the sheer wrong-headedness of the response that beggars belief.

"I mean, your society's broken, so who should we blame? Should we blame the rich powerful people who caused it? No, let's blame the people with no power and no money and these immigrants who don't even have the vote, yeah, it must be their fucking fault."

Banks's death came only a week before his final novel, The Quarry, was published and only two months after he announced his own bad news on his website, describing himself as "officially very poorly".

His work, including The Wasp Factory and The Crow Road, and the Culture science fiction series, was equally admired by critics and popular with the public. However he did have one regret about The Quarry, which was 90% complete and finished on a laptop in hospital after he was given the diagnosis.

"If I'd known it was going to be my last book, I'd have been quite disappointed that I'm going out with a relatively minor piece … the real best way to sign off would have been with a great big rollicking Culture novel."

A central character in The Quarry is dying of cancer – but when Banks began the book, he did not know of his own prognosis, otherwise he would never have written it, Hartley said, in a post added to the Banksophilia blog. She wrote: "The inaccuracies appearing about why and when this book was written make me think of Guy, in The Quarry, gleefully misquoting Dorothy Parker when he exclaims: 'What fresh bollockry is this?'. Iain knew that had he survived his cancer, he would have spent the rest of his life correcting the facts at every event and in every interview!"

She adds: "The Quarry is beautiful. It's a breathless read, laugh-out-loud funny, heartbreaking and fantastically sweary in a way that would definitely meet with Malcolm Tucker's approval – and all the more devastating because in the end Iain came to know his character's story just a little too well. The vicious irony of the situation wasn't lost on either one of us.''

In the interview, Banks allows one other regret: lamenting that his bookshelves could never keep up with his stock of new books, he pointed to one stack and remarked: "That pile there are all unread. And, sadly, likely to remain so."