From Slow Horse to smash hit, author heads Down Under

Spies are supposed to keep a low profile and one gets the sense novelist Mick Herron is most comfortable doing the same.

But the wildly successful author of the Slough House espionage series is visiting Australia for the first time and has already sold out several events in Melbourne and Sydney.

Speaking from Oxford, the unassuming Herron says it's somewhat bewildering to be in such high demand on the other side of the globe.

"It always surprises me when I have audience demand on any side of the world, to be honest," he told AAP.

It's understandable, really: before the bestselling novels and Slow Horses television series, Herron was a sub-editor for a legal journal, writing novels after hours.

Slow Horses, the first book in the Slough House series, wasn't much of a success when first released in 2010, and only became a hit after it was republished in 2015.

The novels have since been adapted into the Apple TV series starring Sir Gary Oldman, Jack Lowden, Jonathan Pryce and Kristin Scott-Thomas - complete with a theme song by Mick Jagger.

Sir Gary plays flatulent, politically incorrect spymaster Jackson Lamb, who oversees a dysfunctional department of failed MI5 spies.

In grubby overcoat and greasy hair, he delivers lines such as: "Bringing you up to speed is like trying to explain Norway to a dog."

Jackson Lamb is driven by self loathing, explained Herron, but he's reluctant to examine exactly where in his subconscious the character has sprung from.

"I suspect it's something to do with the joy we all take in the unfiltered nature of our inner selves, the stuff we think we would never say out loud," he said.

Herron, 62, hastens to add that the human ideal is behaving with respect and consideration, and he's in no way an enemy of political correctness.

He's well aware of the issues facing writers' events in Australia of late, most notably the cancellation of Adelaide Writers' Week in January following the dis-invitation of an Australian-Palestinian author.

The internet has made everywhere a battleground, says Herron, who feels most of the booklovers at these events just want to hear writers talking about their work.

"I certainly know I would sooner just turn up and talk about books; I'm not going to arrive with messages that I want to inform people about," he said.

Despite all this, his novels are brimming with political commentary: the latest instalment is Clown Town, inspired by the real-life Stakeknife scandal, in which the British Army recruited a murderous IRA enforcer as an informant.

Herron never plans more than one book ahead but he says mildly that the tale of Slough House will come to an end at some point.

"I would rather supply an ending than just pop my clogs and have somebody else make up their own," he said.

Mick Herron appears at Sydney Writers' Festival May 17-24, at an out-of-season event for the Brisbane Writers Festival on May 19 and in Melbourne, presented by The Wheeler Centre, on May 21.