Do you mean in the green belt?
Four Tory London councils have refused to participate in a review of London’s green belt led by Sir Sadiq Khan’s office. The review will examine rural
harrowonline.org
More to it than that. You'd want the Thames flanked by high rise buildings right back to Oxford?
I think it's more to thwart BANANAs
Build absolutely nothing anywhere near anything
By they I assume you mean the current government.
If they build affordable housing in the north would you object? Plenty do (no poor people in this area please) and developers won't like it - they prefer building for people who want a big house with space for four cars and object to the section 106 bus service going past then join the chorus of people complaining about traffic.