It comes amid a continuing furore over the controversial sale, which Labor MP Amanda Fazio on Thursday likened to social cleansing in Nazi Germany.

The government has collected $11.1 million from the first four property sales. A further 289 properties are yet to go under the hammer, including 79 apartments in the Sirius building at The Rocks.

The sales program is on track to inject more than $500 million into the government's coffers, but Community Services Minister Gabrielle Upton has refused to say exactly how the windfall will be spent, saying only it will be returned "back into the social housing system".

A crossbench parliamentary inquiry into social, public and affordable housing this month found the spending detail provided by the government was inadequate.

The government says the sale will relieve taxpayers of high maintenance costs and rental subsidies, and help alleviate the long wait for public housing.

However, the absence of both economic modelling and an up-to-date public housing policy has stoked fears the proceeds will be used to fill a gaping hole in the public housing maintenance budget, rather than building much-needed new dwellings.

The inquiry's committee, dominated by conservative MPs, was "dissatisfied" that the government could not say what proportion of Millers Point and Sirius sales proceeds would be used on new housing supply.

Millers Point: a community under the hammer

It called on the government to invest the proceeds from all public housing sales into a fund dedicated to building new homes.

When selling multi-unit properties in Sydney such as the Sirius building it said the government should also require the buyer to allocate at least 10 per cent of all dwellings to social, public and affordable housing.

Figures show the present social housing waiting list of 58,000 households will blow out to at least 86,000 by 2016. The report reiterated concerns by the NSW Auditor-General last year that selling public housing to fill a budget shortfall was "not financially sustainable".

Labor MP Sophie Cotsis, a member of the committee, said offloading properties to fund a maintenance backlog was "like selling your house to pay off your credit card".

Ms Fazio said in the NSW upper house on Thursday the government had failed to produce a plan to solve the public housing crisis after more than three years in office.

She described the Millers Point sale as "a bizarre social experiment ... eradicating a whole suburb", adding "it's not much different to some of the eugenic stuff that was being practised in Germany in the 1930s".

Ms Upton said the Millers Point sale would provide "more homes for more people", describing Ms Fazio's comments as "abhorrent".

She said the government was examining the inquiry's 41 recommendations, but did not say what proportion of sale proceeds would be used to build more homes.