Ms Berry, who is now in her sixth rented flat since moving to London 25 years ago, pledged to strengthen tenants’ rights as she unveiled her first plans in the race for City Hall.
Imposing rent controls on landlords is currently beyond the power of the mayor but Ms Berry, who came third in the 2016 mayoral race with more than 150,000 first-preference votes, said she would lobby for “protection from soaring rents”.
Rent controls are also being sought by Sadiq Khan, who is running for re-election.
According to the Greens, the average tenant in London pays 40 per cent of their income on rent.
Ms Berry said: “London needs a mayor who will be a real champion for renters, bringing down skyrocketing rents and bringing up the standards of housing.”
Her plans include winning rent control powers, fighting for the end of no-fault evictions and supporting tenants to establish co-ops to buy out their landlords.
She would seek a two-year freeze in private rents.
Ms Berry said: “As a private renter myself, I know the reality of being a tenant in London. As Mayor, I will stand alongside millions of renters like me.
“I will push the Government until London gets the powers we need. Almost every other major city has lower rents than London.
“Almost every other EU country has better protections for tenants. London needs a Mayor who will be a real champion for renters, bringing down skyrocketing rents, and bringing up the standards of housing.”
Ms Berry was backed by Georgia Elander, 25, who spends £775a month on a small room in a flat shared with two other people in Clapton.
She has faced problems such as damp, a collapsed ceiling, and rain coming into the kitchen.
“I’ve had to put up with some shocking stuff as a tenant, especially for the amount of money I hand over from each pay packet,” she said.
“For the first three months I lived in this flat, there was literally a hole in the roof, and serious damp which had a real impact on my flatmate’s health – and this isn’t even the worst rented home I’ve lived in.
“I know my story isn’t unique. Almost everyone I know my age is in exactly the same position. We can’t save, there’s nowhere left in London that’s affordable, and rent only seems to go up. We desperately need a Mayor who takes renters’ rights seriously – someone who will make it cheaper to live in nicer homes.”