The fear of losing planning powers has been outlined as a major factor behind the objections of district councils to the creation of a South Downs national park.

A public inquiry into whether the Downs should be awarded the special conservation status heard yesterday that objections raised by Mid Sussex and Wealden District Councils included concerns about the loss of powers to control development.

If the status is granted, a national park authority will be set up to take over the park's management.

Countryside Agency barrister Robert Griffiths said: "The big sticking point is that the authorities want to maintain their planning powers.

"But the principle is that planning should be the responsibility of the national park authority."

Mr Griffiths said because of the number of local authorities that would be included in the proposed park area, some planning powers may have to be delegated back to them.

Dick Lankaster, representing Mid Sussex District Council, was not convinced.

He said: "There is a principle established with other parks that development control is kept by the national park authority.

"Despite what we are told about delegation, the authority may come under pressure to keep the planning powers - that's our concern."

Greg White, a representative from Winchester City Council, which joined forces with the two district councils to present objections, said granting national park status would create the biggest planning authority in the country.

The park authority would have to deal with between 4,000 and 5,000 planning applications a year, making it a 'monolithic body'.

Aside from the planning implications, other objections to the a park were put forward.

Mr Lankaster said that given the Downs were not deemed fit for national park designation by studies in 1956, 1991 and 1998, it was strange it was being considered again when little had changed.

He also didn't believe granting the status would be in the interests of people living and working in the area.

The Environment Secretary is not expected to make a decision until 2005 and it could be 2007 before a park is operating.