Telscombe Town Council has stepped up its protest over boundary changes to the proposed South Downs national park.

It fears changes could lead to the building of a huge coastal sewage treatment works.

There is concern plans to exclude Telscombe Cliffs beach from the boundaries of the new national park means Southern Water is again considering a planning application for the upgrading of its nearby Portobello sewage treatment works.

The Town Council, following a report in The Argus that Southern Water itself had objected to the inclusion of the beach being within the new park, has written to officials conducting the statutory consultation.

The council insisted in July that the whole of Telscombe Tye, which it bought on behalf of residents, should be included within the national park. Now it has stated its demands to the statutory consultation to the South Downs national park.

The council is demanding the entire Telscombe beach and the area south of the South Coast Road, which is partly owned by the council, should remain within the new park.

A major upgrading of the Portobello works was rejected in March last year following a long public inquiry between October 1999 and 2000.

One of the main reasons why Southern Water was not allowed to build at the site was because it was in an area of outstanding natural beauty (AONB).

However, if Telscombe beach is not included in the boundaries, the beach loses its AONB status and one of the main objections to building the £60 million upgraded work on the beach disappears.

Southern Water is under pressure to build a huge sewage treatment works for the Brighton area.

The company objected to all its sewage treatment centres being within the boundaries of the new national park on the grounds it was inappropriate for sewage treatment works to be within a national park and subject to rigid planning rules.

Telscombe town councillor Dawn Davidson said: "We are re-emphasing the need to keep the whole of the tye within the national park because it is the last piece of undeveloped open space between Newhaven and Brighton, and we do not want to see Portobello resurrected again.

"We all want clean bathing water but the works to enable this should not be in an open space, which is enjoyed by the public."

A Southern Water spokeswoman said: "There is nothing sinister in our objections to having all works taken out of the proposed boundaries of the new national park. We just feel they do not meet the criteria."