Not only that, but 24% of the ruling Conservative Party members of parliament are also landlords, including the housing minister.

Partly that, but also partly that in a constituency based system, there will be a bias towards those who are in the constituency longer. I have to register to vote every time I move constituencies (a fairly regular event for a renter), while those who buy only register once (and can be considered returning customers for the member of parliament).

Wealth (which is correlated with property ownership) is also correlated with voting.