The number of affordable homes built in England in 2015-16 fell to its lowest level for 24 years, new data shows. There were 32,110 built, compared to 66,600 in the previous year, according to figures from the Department for Communities and Local Government. UKCW will make this a priority for 2017.
Ministers said the slump was because of the start of a new housebuilding cycle, adding the government was investing £8bn in affordable housing.
Labour said the figures were disastrous and many "affordable" homes were not.
The DCLG figures showed the number of new homes for social rent fell to only 6,550.
Labour said this was 80% lower than in the party's last full year in power (2009-10) when the figure stood at 33,490.
The number of homes for private rental at "affordable" rates fell from a peak of 40,730 in 2014-15 to 16,550 in 2015-16.
The total constructed for affordable home ownership dropped from 15,970 to only 3,430 over the same period.
Labour housing spokesman John Healey said the figures showed the government was building the lowest number of social rented homes since records began.
He added: "This all-time low results from Conservative ministers who have washed their hands of any responsibility to build the homes families on ordinary incomes need.
"We've seen six wasted years with the Tories in charge of housing.
"They have no long-term plan for housing and they're doing too little to fix the housing crisis for millions of people who are just managing to cover their housing costs."
Mr Healey also said the government was trying to hide its "failure" by branding more homes as affordable - even when they are available at 80% of market rent or have a purchase price of as much as £450,000.
"Public concern about housing is at the highest level for 40 years. Millions of families are struggling with high housing costs," he said.
A spokesman for the DCLG explained the drop, saying: "Delivery is normally lower in the first year of any new housing programme and so these figures are expected as part of a five-year housebuilding cycle.
"Building more homes is an absolute priority for this government, which is why we have doubled the housing budget to £8bn and we now have the largest affordable housing programme in 40 years.
"Furthermore, latest figures out this week show overall housebuilding is at its highest level in eight years and we will be publishing our White Paper shortly, setting out our plans to build more homes and more quickly."
Shelter's head of policy and public affairs, Anne Baxendale, said: "At a time when this country is crying out for more genuinely affordable homes, these figures are not only shocking but unacceptable.
"With 120,000 children set to spend Christmas homeless and in temporary accommodation and a whole generation of private renters living from one pay cheque to the next, the new government needs to get a grip on this problem once and for all."
The Local Government Association said: "If we are to stand any chance of solving our housing crisis, councils must be able to replace sold homes and reinvest in building more of the genuine affordable homes our communities desperately need now more than ever."
Terrie Alafat, chief executive of Chartered Institute of Housing, said: "Though a drop in the delivery of affordable housing may have been expected following last year's peak, the fact supply has more than halved in a year is extremely worrying.
It was now clear that the government must introduced bold and targeted measures to deliver its pledge to tackle the growing housing crisis, he added.
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