Cameron, visiting a previous government supported housing development, was asked by the BBC whether it was wise for the government to enter the mortgage market in such a way.
He said that the scheme would simply help people get onto the housing ladder and would not encourage reckless lending.
“We don’t want to go back to 110% mortgages and people buying homes they can’t afford,” Cameron said.
“Right now you have a situation where two hard working people both bringing in a good wage should be able to buy a flat or house of their own and they can’t. That needs to change and that’s why this scheme is so important.”
Help to Buy formed a key part of the Budget announcement in March but has been heavily criticised over the possibility it could subsidise second homes for the richest people in the country.
The equity loan component of the two-part scheme launched at the start of the month and the mortgage guarantee aspect will start in January 2014.
“I think everyone will welcome the fact that we are trying to get the housing market moving because in an economy, to function properly, you need people to be able to buy a home, get a first foot on the housing ladder. These are changes that need to take place and will benefit everyone.”
Council of Mortgage Lenders chairman Nigel Terrington added his voice to the criticism of the scheme on Friday, saying the government needed to abandon ‘sound bite’ mortgage and housing policies.
“For political reasons over recent years we have seen the rise and fall of many housing and mortgage schemes; in fact, more policies – and more years – than many of us will care to remember,” he told an audience in London.
“Isn’t it reasonable for lenders to question the longevity and reliability of any schemes brought forward by the government of the day, where the same has not published clear objectives, success measures and provided a landscape of how these will be evaluated?”