Thousands of planned new homes are at risk after a series of local authorities cut or delayed their housebuilding plans.
The move follows the decision by ministers to drop mandatory building targets following a revolt during the passage of the Levelling Up Bill.
Nine local authorities in England have paused or scaled back their plans after Michael Gove announced last month that the government would no longer pursue a mandatory target of 300,000 new homes a year.
They join nearly 30 other authorities that made similar decisions while they waited for Westminster to make a decision on its targets.
Analysts are now warning that the confusion over housing policy could cost 100,000 new homes over a five-year period.
