Sadiq Khan will release his proposals for a 'London Living Rent' soon.
However, he feels the conservative government will block any attempts to introduce legislative rent controls, so will look to the Living Rent to make London more affordable.
The London Living Rent will be set to one-third of the average local income, which would equate to about half of the present London average rent.
Adam Challis is the head of residential research at Jones Lang Lasalle and spoke to the Financial Times. He said: "Although the policy has been described as a form of rent control, it should more properly be termed as 'rent indexing'. It will have the advantage of offering those who built the homes some sense of certainty about what their rental income would be in the long-term."
Challis also suggested that the London Living Rent could effectively replace 'affordable rent' homes that are being built as part of new housing developments.
Khan has also proposed a not-for-profit lettings agency "for good landlords" to give tenants confidence and limit high fee charges. However, this has yet to be quantified or set out.
He will also make an online, publicly available list of rogue landlords who have either broken the law or charged unfair fees.
One of Sadiq Khan's most popular, and perhaps game-changing proposals, is to encourage build-to-rent properties designed specifically for professionals to rent while they work in the capital. He will try and accelerate delivery of new units and, in turn, encourage investors to perhaps consider more buy-to-let opportunities in London.