As the sun rises on Park Lane Maria sticks her head out of her tent and squints at the Aston Martin showroom across the road. Around her, others unzip their doors, stretch and slip on flip-flops before heading to a camping stove where a boiling pan of water will be poured into mugs piled high with instant coffee.

Anyone who’s played Monopoly will know this campsite sits on just about the most valuable piece of land in London. For those wishing to stay at one of the neighbouring hotels, like The Dorchester or 45 Park Lane, rooms cost a minimum of £1,000 a night.

Despite London mayor Sadiq Khan pledging in his…