Oxfordshire is facing a social worker “crisis”, according to the Conservative Party, which claims one in 12 such posts at the county council are vacant.

The Tories said the figures showed more than eight per cent of social worker posts in Oxfordshire were unfilled, with the shortage blamed on low staff morale, caused by “excessive bureaucracy” imposed by Government.

The figures, disclosed under the Freedom of Information Act, refer to the state of the profession last November.

Tim Loughton, the Tory spokesman for children, said across England there had been a 30 per cent rise in vacancy rates since 2005, from 11 per cent to 14.6 per cent, based on figures from 52 local authorities.

More than half of local authorities had a vacancy rate higher than 10 per cent, prompting concerns about child protection, he added.

In eight local authorities – including Haringey, where the mother of a 17–month old infant known as Baby P, and her partner tortured and killed the infant despite social services putting him on the at-risk register – at least a third of posts were unfilled.

The Conservatives said Oxfordshire’s vacancy problem, although less serious than that of other councils, was still a cause for concern.

Children’s Secretary Ed Balls hit back, saying the Conservatives’ spending proposals would see the non-schools budget of the Department for Children, Schools and Families cut by £300m.