Last week, I betrayed the homosexual parenting community. At Elton John’s insistence I tried to boycott Dolce & Gabbana, which was a great sacrifice for me, as other designer underwear makes my testicles look old.

As I have been appearing at a theatre in Dundee it has been difficult to find any Dolce & Gabbana outlets to boycott. Instead, I located a second-hand copy of Joe Dolce’s Shaddap You Face single in Groucho’s records on the Nethergate, and pointedly refused to buy it.

But it has been a troubling week. News events, coupled with the liminal experience of spending time in Dundee, have conspired to make me doubt my own existence. And that of others. And that of all matter. It is the fault of the government.

Earlier this week the Conservative party chair Grant Shapps was revealed to have operated, even while an MP, a variety of ethically translucent internet business funnels under the alias of Michael Green, pseudonymous author of a book called How to Get Stinking Rich. Grant Shapps even wore a badge saying he was Michael Green at a 2004 conference, though apparently this was a joke, but one so subtle that many people took it at face value. Now he knows how I feel writing these columns.

Green, a non-existent man, marketed software that steers Google search engines towards particular information, manipulating our perception of reality. Fittingly, most traces of this Michael Green’s HowToCorp company have since been erased from cyberspace, perhaps by his own software, jammed in reverse gear with an imaginary spanner.

How disorientating. Some 25 years ago now, in 1990, a young Grant Shapps hired me as the sole employee of his profitable live bait vending business, House of Maggots, which I didn’t over firmly deny in the Observer last March. Grant Shapps and I spent many a moonlit night at popular Suffolk angling spots filling roadside fridges with comatose larvae, discarding maggots that failed to thrive, talking about our dreams. But who was the Grant Shapps that I imagined I knew all those years ago?

In August 1989 Grant Shapps had a car crash near WaKeeney, Kansas, on Interstate 70, his companion probably falling asleep at the wheel. Speaking to the Welwyn Hatfield Times in 2011, at the opening of a refurbished McDonald’s in the region, Grant Shapps confessed: “I was in a coma for the best part of a week and when I came round I recuperated in a Ronald McDonald home. I’ve always been grateful to Ronald McDonald.” Could this bizarre incident be significant?

The spring of 1989 saw a surge of UFO sightings in Kansas, clustered principally around the town of Russell, 60 miles west on Interstate 70 of Grant Shapps’s subsequent accident. The UFO-spotting season closed spectacularly in November 1989 at Goodland, 111 miles east, on the same road, when two women were abducted by aliens, and left unable to account for three hours of their evening. And in between those two spates of alien activity, geographically and temporally, lies Grant Shapps’s own crash and coma. Could this be the point at which the reality-moulding entity known as Michael Green somehow took possession of the future Conservative party chair? Did Grant Shapps’s Kansas blackout provide a gateway for the little Green man?

Given this Michael Green’s self-professed ability to use software to rewrite our perception of our own history, and our own reality, I wondered if there ever was a “Grant Shapps”, as we understand him, at all? Grant Shapps’s Wikipedia entry is known to have been regularly and favourably massaged by unseen hands. But are these hands alien hands? Are they green? Could this Michael Green have inserted a rebooted “Grant Shapps” character, who never really existed, into our reality by a similarly deft manipulation of online records?

And what kind of name is “Grant Shapps” anyway? Say it a dozen times. Roll “Grant Shapps” around your tongue. It sounds, as does Douglas Adams’s pitch-perfect Ford Prefect, like the kind of name an alien would choose in a bungled attempt to appear human. And so does “Ms Stockheath”, one of Michael Green’s supposedly satisfied online customers, and a name no one in the world has ever had. Ever.

Writing in the London Review of Books in January, Andrew O’Hagan showed how easy it was to use online resources to build a non-existent man from the ground up, who eventually took on a viable virtual life. And of course, members of the police have famously created similar false identities in order to have sex with Guardian readers and befriend Mark Thomas.

Is Grant Shapps the creation of this Michael Green? And if so, who are we? Has this Michael Green, or this Grant Shapps, micro-engineered a virtual world in which we also believe we exist, when in fact we may not? Are we just ciphers now, clumps of sentient meat, plugged into sockets, farmed by Michael Green or Grant Shapps, but for what? Data? Energy? For some super-being’s sick fun? Are we maggots dreaming of Grant Shapps, or is Michael Green a vast consciousness that dreams Grant Shapps daily into being?

I leaned against the outside wall of a public toilet near a building site on the banks of the Tay and rang a mobile number Grant Shapps had given me 25 years ago, in case of nocturnal maggot emergencies. Back then it had connected to the brick-sized carphone in his maggot van. Now a trim buzz broke off suddenly and Grant Shapps, identifiably and audibly Grant Shapps, snapped “Who gave you this number?” Instead of asking for Grant Shapps, I said: “Is Michael Green there?” “Michael Green is here,” came the reply, “but who and where, I wonder, do you imagine you are, my meddling maggot?”

And then everything went wobbly. The surface of the Tay seemed to shimmer, the grey light rolling over the estuary from Tentsmuir Forest frazzled and burned, and the Tay Bridge buckled and bent. The brick wall at my back melted and my internal organs fused, air in my guts and liquid in my lungs. In the purple cloud above the boiling river I swear I saw the face of Grant Shapps, or Michael Green, or maybe even God, looking down and laughing, his hands full of wriggling maggots, tumbling into his open mouth. “Am I dead now?” I cried.

“Come on,” said my tour tech, James, snapping me out of it, “we have to get to Inverness today.” And everything went flat again. And we drove north across the Cairngorms dusted with snow, looking for all the world exactly as one would imagine mountains would look.

Stewart Lee’s A Room With A Stew is now touring and will be at Leicester Square Theatre from 21 September 2015. stewartlee.co.uk