The B.C. government is committing to put an additional $335 million into social housing projects over the next five years, most of it from transfers of property to non-profit societies.

Premier Christy Clark announced the social housing program before this week's provincial budget, calling it "the largest single social and affordable housing investment in the province's history."

That description was targeted by the opposition, who said it represents a reduction in the commitment made in the government's 2015 plan. NDP housing critic David Eby said Monday the announcement by Clark and Housing Minister Rich Coleman came after the government was caught redirecting proceeds of social housing sales to general revenue.

"Under this program, the province sells public assets, social housing across the province, to non-profit organizations," Eby told the legislature. "Unfortunately, when they sell this social housing, they do not and they cannot, because of the economics, guarantee that all of the units will continue to be rented at non-market rates. That's rents affordable by seniors, to people with disabilities, to families living in poverty.

"A significant number of these units will be rented at what he called market rates, which is a fancy way of saying rates that are not affordable to the people who used to live in those units."

The B.C. Liberal government's plan to invest directly in new social housing is a change from Coleman's past policy to focus on rent subsidies rather than direct spending on social housing. The province currently pays rent assistance to nearly 30,000 low-income seniors and families, and funds another 41,000 in independent social housing.

The latest commitment is to expand social housing with $50 million in the fiscal year that starts April 1, another $50 million the following year, $75 million in 2018-19 and $90 million each of the next two years.

Coleman said the money comes from the province's non-profit asset transfer program, begun in 2014.

"Its success is allowing us to reinvest money back into affordable housing across the province, while also helping non-profit societies secure the financing they need to be sustainable," Coleman said.

The B.C. government defines "affordable housing" as costing 30 per cent or less of the household's gross income.