Millions of pounds are expected to be spent on a public inquiry called to decide if the South Downs should be designated a national park.

The Government announced the decision to call in the proposals for public scrutiny yesterday, infuriating pro-national park campaigners who said it was a waste of time and taxpayers' money.

The chief objectors, East Sussex and West Sussex county councils, have earmarked £250,000 to fight the proposals.

The Countryside Agency expects to spend another £2.5 million defending the scheme.

Other local authorities which have objected to the national park in principle include Chichester, Mid Sussex and Wealden district councils.

In a written statement to Parliament, rural affairs minister Alun Michael said: "The National Parks and Access to the Countryside Act 1949 requires an inquiry be held into a Designation Order if a local authority has objected and the objection is not withdrawn.

"Several local authorities have made objections and have so far not withdrawn them. Consequently, a public inquiry will be called."

However, hundreds of people across Sussex have supported the plans, which would give the Downs a similar status to other English national parks such as the Peak District, the Yorkshire Dales, the Lake District, Dartmoor and Exmoor.

More than 5,500 letters were sent to the Department for the Environment, Food and Rural Affairs after the order was published in January.

Many supported the proposal, while the majority of objectors wanted the boundaries altered to have more land included in the national park.

Supporters and opponents of the park will put their case at the inquiry, which is expected to start in November and last 12 to 18 months.

National park campaigners have been infuriated by the opposition of the local authorities.

Chris Todd, of the South Downs Campaign, said: "We feel it is a complete and utter waste of money to be examining the principle of the national park when it is supported by the majority of people.

"This is at a time when people are seeing huge rises in council tax. We have two county councils in Sussex spending public money fighting something the public wants. It is scandalous."

Beccy Reynolds, campaign officer for Bricycles, the Brighton, Hove and District Cycling Group, said: "East Sussex and West Sussex should not be opposing the park given that the people want it.

"We're not happy with that, especially with the recent council tax rises. They could have saved money on the public inquiry and kept council tax lower."

East Sussex County Council Leader Peter Jones welcomed the inquiry and said many issues needed to be discussed in the public domain before any decision was made on the future status of the South Downs.

He challenged pro-national park campaigners to prove the majority of people wanted it.

He said: "If you go shuffling up to the man in the street and ask them if they want a national park, 90 per cent of them will say yes."

But he said campaigners were not acting in the best interests of the people.

Mr Jones said he wanted to spend as little as possible on the inquiry and the council had earmarked £50,000 for its case.

He also challenged all sides to forgo lawyers to make the process cheaper.

The park is not expected to be operating until 2006/07.

The South Downs is the only area identified as being of national park quality in the Forties never to win the special conservation status.

Deputy Prime Minister John Prescott announced plans to create a national park in the South Downs as a millennium gift in 1999.