National park campaigners are expecting people in the South Downs to buy a pig in a poke, a public inquiry was told.

East Sussex County Council, one of the main objectors, said it was uncertain how well the park would be funded or how much a new bureaucracy would cost.

Assistant environment director Stephen Ankers said the council did not dispute the South Downs was of sufficient landscape and recreational quality for a national park.

But he said local authorities had a long record of protecting the Downs and a park could syphon Government and European cash from elsewhere in East and West Sussex.

He said: "It is therefore the county council's belief that it and the local community are, in the words of key members of the council, being asked to buy a pig in a poke." West Sussex County Council told an earlier session it was being expected to accept a blank cheque, and Mr Ankers said his authority wanted an assurance it would not lose money if a park was set up.

He said local authorities had played a key role in setting-up the existing Sussex Downs Conservation Board, which should be strengthened rather than replaced.

Councils have long argued they should retain control of planning, rather than pass responsibility to a ruling national park authority.

Campaigners, meanwhile, claim the existing body is underfunded and does not have enough clout with councils to properly protect the Downs.

The Countryside Agency said a national park would attract £5.8 million a year according to the most recent estimate, about three times the conservation board's annual spend.

The inquiry is scheduled to sit until September. The Environment Secretary is not expected to make a final decision until 2005.