Let this post of mine be the last that mentions politics in this thread, please.
I was born in a country that has imposed caps to most rents for decades and has very tenant-friendly laws. Result: dire shortage of properties to let. The only letting activity that people are happy with is AirBnB. Why should a landlord let out a property if they can barely pay the mortgage with the maximum rent they are allowed to ask for? While at the same time throwing out non-paying tenants is almost impossible because the law defends them as opposed to the landlord? I certainly won't keep my parents' property and let it out once they're gone - that would be madness. I'll sell it straight away.
So I wouldn't blame the Tories or indeed any other party for what happens in this country. In places like London, regardless of politics, one of the problems appears to be the marketing of all new properties under construction to wealthy overseas buyers even before those properties are made available to (usually slightly less wealthy) locals. And then many of those properties are bought as an investment and left unoccupied. Another problem is the lack of affordable housing - developers of new builds appear to use a very flexible definition of "affordable" and, even when a percentage of the new properties is described as affordable, what it boils down to is that some of the new flats in the build are simply less outrageously expensive than others, but still far from affordable to the majority of those who need them.
There is no easy solution.