Playing fields and homes for the elderly head a confidential list of county council-owned sites in Oxford that could be used for housing.

The list includes the council's main offices - County Hall, Speedwell House and Macclesfield House, Cowley Marsh and Northway playing fields, Ormerod special needs school and a greenfield site in Grandpont.

With consultation under way on where new homes should be built in the city, green campaigners say that 14 key sites being looked at have been kept secret.

The CPRE (Campaign to Protect Rural England) used the Freedom of Information Act to get Oxford City Council to release the list of potential development sites it asked the county council to draw up.

CPRE spokesman Andy Boddington said the list made nonsense of a consultation to find where the public thinks new homes should go.

He said: "The decision by the city council to keep confidential 14 of the 33 sites it has put out for consultation is shocking. How can people comment on sites that have been kept secret?"

The list includes four county council owned homes for the elderly: Townsend House, Barton; Iffley House, Iffley; Marston Court; and Longlands, Blackbird Leys.

County Hall estimates that Cowley Marsh playing fields has capacity for about 118 dwellings, while Northway playing fields was said to have room for 90.

Of the Grandpont site, the report said: "Much of the site is in the floodplain, so only the area outside flood plain considered."

City council chief planning officer Michael Crofton Briggs said the city had asked County Hall to come up with the list to assist its long term planning.

He said the county had asked for the sites to remain confidential.

He added: "We did not want people to put two and two together and make 79.

"It does not mean that there should be a presumption that all these sites should be developed."

Peter Taylor, county council asset review officer, said the sites were submitted confidentially to avoid causing "unnecessary concern or misunderstanding to those using the buildings." He said no decisions had been taken.

"The county council is acting prudently to ensure that sites with future potential are given consideration; they are not proposals for sale or redevelopment," he said.

Roger Davis, of the Oxfordshire Playing Fields Association, said: "We have to recognise that some housing development has to take place.

"But we are against trade offs where accessible green areas are traded for hard multi-use games areas operating on a pay-to-use basis."