Limit London property rental to average maintenance cost

Fact 1. Londoners without property must pay a large and ever increasing proportion of their hard earned income to their landlord as rent.

Fact 2. The market value of rent in London is generally far higher than the long term cost of property maintenance.

Property owners in London therefore often have a rental income which is well above the cost of maintenance. How can that be morally justified?
The rate of extortion from tenants to landlords has been steadily increasing for decades, to the point now where even middle income Londoners are increasingly being forced to leave their home town. Property ownership removes the need to pay rent, but why should it also give anyone the right to an unearned income? Limiting the maximum property rental in London to the average cost of maintenance would be a long term solution to the problem of accommodation costs in London. The incentive to buy would remain as the prospect of paying a large chunk of your salary every month into your own pocket rather than someone else's. The squealing which this would induce in rich win-win property investors would of course be deafening!

FAQs for this campaign are listed here: https://sites.google.com/site/limitlondonrents/home/faqs