Speaking at the Policy Forum for London Keynote Seminar, he said only “radical solutions” can solve the problem, such as rent stabilisation tracking inflation.
Lammy said: “This is a very important subject – probably the most important facing our country at the moment.
“When politicians use this phrase ‘we now want to build affordable housing’ we are getting to the stage where people want to pelt us with tomatoes and apples because what we are talking about will not be affordable to them, when average earnings are around about £32,000.
“How do you make that rent in the London borough of Camden of £1400 per month?
“In my borough of Haringey rents have risen by 20% over the last two years, Richmond 40% over the last two years.
“My own view is that we will need some radical solutions. I do think politicians and certainly the Labour Party is committed to some kind of rent stabilisation; some kind of Germany-style inflation index-linked cap.”
He stressed that while building homes is crucial, the focus should be on quality as well as quantity.
He added: “In this rush to build; where all political parties say we need to build, I actually don’t want to see a new generation of Broadwater Farms.
“In my experience there are very few politicians, very few architects, very few planners who grew up in some of those housing estates and we need to not make those same mistakes.
“Design is really, really important in establishing how we get density.”