Boris Johnson, parliamentary candidate for Uxbridge and South Ruislip, will not build on Hillingdon's green belt despite calling the housing crisis an "acute problem we are struggling to deal with in London".
The comments were made at the latest parliamentary hustings at St Margarets Church, Uxbridge, on Friday (April 10).
The Mayor of London also praised the multi-million pound St Andrews development under way at the old RAF Uxbridge site.
He said: "A classic example of good, sensible improvement in Hillingdon would be the St Andrews Park development, which is family housing and it's for Londoners.
"If you build high rise rabbit hutches it would destroy the quality of the neighbourhoods. It is an acute problem that we struggling to deal with in London."
The Conservative candidate's comments come just before his party announce their national manifesto, in which a key pledge is to extend the Right to Buy scheme to housing association tenants in England.
But Labour candidate, Chris Summers, thinks not enough is being done locally to utilise the land on offer in Hillingdon.
He said: "The other day I was canvassing in St Helen Close, Cowley, and there was a huge piece of land that probably could have fitted five or six houses. It was completely derelict and looked like it could have been like that for several years.
"Part of the problem is the planning system - it's too reactive, not proative."
Paul Ouro, 34, a landlord who owns properties in Cowley, tries to keep his rents below market value.
He told getwestlondon: "I think the mortgage lending behaviour could help the housing crisis.
"Before the rates were high but people could easily borrow. Now, 20 to 30-year-olds have to rent - it's the old cliche, the rich get richer and the poor get poorer!"
Mr Johnson suggested ways young people struggling in the borough could leave the renting trap: "They need to be helped with schemes that are specifically targeted at people who cannot afford the cost of a mortgage. Our first steps schemes will subsidise mortgages to help people onto the property ladder."
This was voters last chance to ask questions to the current Mayor of London, as this was the only hustings he will attend.