The housing crisis is the great issue confronting our capital. More and more Londoners are being priced out of their home city. The government and the current Tory mayor have failed to build anything like enough new affordable homes. Overseas investors have been allowed to distort the market.
Housing matters most to people, not just because it affects their lives here and now, but also because they know this issue will affect our great city's future well-being and fundamental identity.
Getting housing right over the next decade will go a long way to deciding if London is somewhere ordinary families can afford to work and live, or if our great city becomes hollowed out to the detriment of the diversity and social mix that helps make it such a special place.
Zac Goldsmith has finally released his plans for housing. He claims to understand the difficulties Londoners are facing, but nowhere does he define what he thinks would make a home affordable to rent or buy.
What we do know is that he thinks £450,000 is an affordable price for a first home. Zac Goldsmith voted for the Housing and Planning Bill last November, which set out that 'starter homes' - new builds for first-time buyers - in Greater London can cost up to £450,000, a phenomenal amount of money for most working people.
Zac Goldsmith could have used his manifesto to make a commitment to pricing newly built homes for first-time buyers at lower than £450,000. He didn't.
We shouldn't be surprised. The provision of affordable housing, social rents and preserving an urban environment's social mix are alien concepts for Tories. That's why Boris Johnson has done nothing as social and private rents have soared. And that's why Zac Goldsmith has done nothing in his manifesto to convince Londoners he'll build homes they can afford.
My manifesto sets out the clear target that 50 per cent of all new homes build across London will be affordable, and presents clear plans of how to help ordinary Londoners purchase or rent a suitable home.
By setting up Homes for Londoners - a new and powerful team at the heart of City Hall - I will bring in new experts and bring together all the Mayor's housing, planning, funding, and land powers.
I will build an alliance of those with a stake in building new homes for Londoners - councils, housing associations, developers, home-builders, investors, businesses, residents' organisations - working with me as Mayor of London to set out what we need from central government to enable us to build more homes.
Alongside homes for social rent, the new London Living Rent will offer homes for people struggling to rent privately, where rents are based on one-third of average local wages.
We will create the opportunity for first-time buyers to 'part-buy part-rent' on mayoral and other public land. My aim is to cut their cost and give first dibs to Londoners who have been stuck renting for over five years - especially in outer London where the biggest falls in homeownership have been seen.
Zac Goldsmith also talks about creating a chief architect for London and "flying planners", and a nine-month "Mayor's Mortgage" for first time buyers. This latter idea only adds three further months to existing six-month mortgage offers, when the problem is that flats in new developments are all too often being snapped up by cash buyers from overseas years before they're built. Perhaps I should be flattered by the other suggestions, because to my mind they follow, albeit with less clarity, my Homes for Londoners plan.
In the midst of this unprecedented housing crisis, London deserves a mayor who will truly appreciate their needs, and not, as the current Tory mayor has done, undermine councils' efforts to build affordable housing by overruling them.
I want to see a city that gives the same opportunities to my children as my parents were able to give to me. Growing up on a council estate in Tooting means I appreciate the value of social housing. It might not have been grand, but it was stable, sufficient and reasonably priced and gave me and my siblings the foundation required to build our own lives. I also scrimped and saved with my wife so we could afford a deposit to buy our own home so I know how difficult, if not impossible, it must be for today's first time buyers.
It's these experiences that shape my vision for our capital - a city where buying or renting a home for young people on average or below-average incomes is a reality and not a fantasy.
Sadiq Khan is the Labour MP for Tooting and Labour's London Mayoral candidate