It has been claimed that Oxford's bid to become a city of culture could be threatened by increasing amounts of rubbish dumped along the city's ring road.

Campaigners are now stepping up their efforts to tackle the problem.

They claim district council boundaries are making it hard to get the matter dealt with.

We can't just go in and do it whenever we want, we have to bear in mind safety considerations Councillor Tony DeVere

White Horse Vale, South Oxfordshire, Cherwell District Council, and Oxford City Council are all responsible for parts of the road's verges.

Members of a campaign group which petitioned for five years for the speed limit on the A34 through North Hinksey to be reduced have taken on the challenge.

Campaigner Marion Haing said: "The ring road comes under four different councils, so it's very difficult to get answers, but I imagine that if the reason given by one council is correct, that they are not clearing the road for health and safety concerns, then it's probably the same with the rest of them."

Councillor Tony DeVere, a member of the Vale Council executive responsible for waste management, said:"Costs play a part, and especially now, safety.

"We can't just go in and do it whenever we want, we have to bear in mind safety considerations.

"We either need to do it at night, or to close off one lane using cones - this is a specialist and costly process which will not be feasible on a regular basis."

Oxford is one of six cities in the running for the title of European Capital of Culture 2008, due to be announced in May.