One in five people aged between 31 and 44 who do not have children has been forced to delay starting a family due to a lack of affordable housing, a study says.
More than one in four (26%) of those who have put starting a brood on hold also say that they have been doing so for five years or more, charity Shelter found.
It estimated that more than a million people in this age group could be delaying starting a family if the figures were projected across Britain. This could equate to a 63% rise in people putting off having children because of housing costs compared with a similar study carried out in October 2009, the study said.
Shelter said the Government must take radical action to stop an entire generation being held back by a "desperate shortage" of affordable homes.
The charity said that with one in three first-time buyers now aged over 35, the large deposits often demanded by lenders are stopping growing numbers of people from buying a home.
Kay Boycott, director of communications, policy and campaigns at Shelter, said: "It's heartbreaking that so many people are being forced to put their lives on hold in this way.
"Sadly, more and more couples are finding that despite working hard and saving hard, they're still priced out of a stable and affordable home, trapped in rented housing where landlords can evict them or raise the rent at any time. We know that many simply don't think this is a suitable place to raise a family."
Netmums founder Sally Russell said a family home was one of the most basic requirements for raising children, but many people are finding this increasingly unattainable.
She said: "The latest news from Shelter that the number of 31 to 44-year-olds who are delaying starting a family has leapt by two thirds is simply shocking. Sadly for a number of these, leaving it too late may mean they may never able to have children. For others, it could mean both parents forced to work full time when their baby is tiny just to keep a roof over their heads."
More than 5,000 people took part in the research this month across Britain.