After health and safety officials discovered his "homemade" home has no fire escape, Brit eco-warrior Hilaire Purbrick faces the threat of eviction.
Purbrick, a 46-year-old dad-of-four, had carved the cave out of chalky rock himself with a pick and a spade, and ever since officials blocked the entrance to the cave, he has been living in a nearby shed.
"I don't know why I built it, it just felt right," the Mirror quoted him as saying.
"I dug almost non-stop for three months over the winter of 2004-2005, picking out a spiral staircase into the earth.
"It's the most peaceful place down my cave. I played my fiddle there and a guy taught me some very powerful meditation. There's no interference so I could make my brain waves travel at the same speed as atoms, nine-tenths of the speed of light," he said.
But now that Brighton and Hove Council have won a court order to kick him out, he has vowed to go to the European Court of Human Rights.
"I don't understand why they have got it in for me. I don't claim a penny in benefits and I see myself as a guardian of this land, which is open to anyone," he said.
The cave is just 10ft by 15ft, and it houses a double bed, bunk bed, stove and desk.
There is no electricity, no TV, no central heating and no fridge, and the only items linking him to the 21st century are his new mobile phone, a wind-up radio and torch, a solar-powered battery and a gas hob.
Purbrick's passion for self-sufficiency came about after his clown shoe design business went up the spout and his first wife gave birth to their daughter, Molly, now 17.
"That's when I first got an allotment up here and the place was just scrubland. I slowly started moving in and before long, others joined me and we established a legal commune up here," he said.
They were evicted but he moved back to the site in November 2003, and has been there ever since, keeping chickens and growing enough fruit and vegetables to feed the community, with leftovers to hand out to people in greater need.
"After everything we have given to this place it would a tragedy to leave. I must have a negative carbon footprint, as I don't use any electricity, we feed ourselves from the land or from the perfectly good food that supermarkets throw away. The best was some caviar but nobody liked it so we fed it to the chickens," he explained.
"Our toilet is a privy over a deep pit and we use sweet-smelling chaff thrown away by a coffee shop to soak it up and break it down. We have mains water to wash, cook, drink and use on the land. We don't create any rubbish. I live like a king but I don't ask anyone for anything," he added.
Purbrick is sharing the site with a Czech IT genius and a gardener who used to work for Prince Charles at Highgrove.