It would be "irresponsible" not to allow developers to build on greenfield land to avoid the UK falling further behind its housing targets, the Conservative Party was told in Birmingham this week.
The housing shortage, one of the party conference' defining issues, prompted new planning minister Nick Boles' claim.
"There is still a bias towards brownfield land in the national planning framework," he said at a fringe event on Sunday. "But it's not a bias that comes with any price."
Boles told delegates that many brownfield sites were too expensive to be viable without subsidy and, unless developers had access to the cheaper greenfield land, the UK would fall further behind its housing targets.
Developers need to build between 230,000 and 250,000 homes a year to meet demand, the Home Builders Federation has said. They build 110,000 annually at present.
Mark Barrow, Birmingham City Council regeneration chief, said he had identified sites for 43,000 of the 100,000 homes required within the next 15 years, and added that the rest would likely need to be built on greenfield land.
The government also came under fire from developers for "dragging their feet" over releasing public sector land, particularly the Ministry of Defence and Department for Education.
The government owns 30% of the UK's developable land. Despite the relaxation of planning rules in the last Budget and initiatives such as the New Homes Bonus and NewBuy, housebuilders remain sceptical that the problem can be addressed without a substantial increase in bank lending.
Mark Clare, chief executive of Barratt Developments, said that, unless the government increased its Funding for Lending programme, efforts to address the housing shortage would be futile.
Under the scheme, announced in August, the Bank of England is to lend money to banks at below market rates.
The governor of the bank will monitor their progress in lending the money to the public.
Clare said a "step up" in the initiative would provide the "shot in the arm" that would prompt banks to lend to prospective buyers.
"Banks will then start competing for customers and lending will return," he added.