Council chiefs say that a combination of welfare reforms and spiralling property prices could see more London boroughs buying up sites in Kent for social housing.

The warning comes in a report by the county council that assesses the impact of the government’s far-reaching welfare reforms and new benefit caps.

It says that London councils could seek to acquire land and derelict sites for housing, as Redbridge council recently did with the former Howe barracks site in Canterbury.

And it says housing associations fear that a cut in social housing rents of 1% up to 2020 could mean up to 600 fewer homes being built in Kent each year.

With greater funding for housing needs than most councils in Kent, the report suggests London boroughs could be eyeing up sites for their own housing needs.

It says while migration from the capital to Kent is not a new phenomenon and while it can apply pressure on public services, it remains “relatively sustainable whilst movements are well-dispersed.”

However, it goes on to warn: “London boroughs are facing a combination of budget cuts, increasing accommodation need and London housing market forces making the sourcing of social housing and temporary accommodation difficult and expensive.”

As a consequence, the report states “all these factors have resulted in boroughs starting to look outside their areas and London to create capacity.”

It cites the example of Howe barracks as a possible start of a trend that could place already-stretched council services under further threat.

“The long-term lease of accommodation at Howe Barracks in Canterbury to the London Borough of Redbridge is one of the largest cases to date and presents a serious set of challenges to Kent’s public services.”

“Whilst there is no direct link to welfare reform and this could simply be a one-off opportunistic procurement of an unusually large and unique site, Kent local authorities need to remain alert and ready to respond should a broader trend start to materialise.”

County councillors who were presented with the report expressed concerns that authorities would face difficulties meeting the increased demand for services.

Cllr Margaret Crabtree (Con) said: “I don't think this is a one off. I understand the MOD has a number of derelict sites that they would like to use in the same way. If a number of them are in Kent that will have a detrimental impact on school places and social workers that we already have a shortage of,” she said.

David Whittle, the council’s director of policy and strategy, said it had been a surprise when Redbridge outbid Canterbury City Council for the Howe barracks site.

Cllr Alan Marsh (Con) said there was a case for Kent County Council to have powers to build social housing. It was “naive and unrealistic” to expect a cut in rents not to lead to fewer houses being built by housing associations.

“What is required is more houses. Even if it requires primary legislation The county council as a body can take control of some housing we can get through this.”

Redbridge council said this week it had already moved 125 families into the former Howe Barracks site.