A family with young children is faced with the threat of raw sewage bubbling up outside their back door.

Oxford City Council is refusing to accept responsibility for a blocked sewer.

Freda and Alan Hughes, of Moody Road, New Marston, who have two sons, Alistair, nine, and Kenneth, six, first noticed the problem in 1992.

They have had to call out Oxford City Council contractors to clear the sewer on several occasions and it was discovered that the sewer was partially blocked by roots from horse chestnut trees in Harberton Mead.

According to insurers Zurich Municipal, the council does not have to pay for the repairs to the sewer because 16 homes in Moody Road and Peacock Road are responsible for their shared private sewer, which runs under Harberton Mead.

Simon Phillips, of Peacock Road, has investigated the situation and believes that the trees belong to Oxfordshire County Council, but are the responsibility of the city council, which maintains Harberton Mead under an agreement with the county council.

He said: "The reason we feel that we should not have to pay for dealing with a long-term problem is that the blockage is acknowledged to be caused by tree roots in Harberton Mead, on council land."

In January, Oxford City Council served a notice requiring properties with odd numbers in Moody Road and even numbers in Peacock Road to undertake work on the shared sewer within 28 days.

Mr Phillips said the notice caused anxiety to some home-owners because it was written in formal legal language and was not accompanied by a covering letter.

The Hughes family are prepared to pay their share of the estimated £2,000 sewer repair bill to put an end to the health hazard, but home-owners who share the sewer and are not directly affected by the flooding are less willing to pay out.

Mrs Hughes said: "As a parent I really do not like the fact that raw sewage is flooding our patio up to a couple of times a year."

A city council spokesman said: "We have discussed this matter with residents and are making efforts to find out who is responsible for carrying out repairs to this sewer. As soon as we know more, we will be in touch with residents."