Acid-tongued pop Svengali Simon Cowell has threatened a showdown with Southern Water bosses if they take away his poodle's favoured haunt.

Simon, renowned for his curt put-downs to contestants on ITV's Pop Idol, is furious at plans to build a sewage treatment plant near his mother's home in Ovingdean.

Whenever he visits, Simon walks his dog Prancy near the proposed site, between Roedean School and the St Dunstan's centre for blind ex-servicemen and women.

He has written a letter to Southern Water bosses, urging them to consider other locations rather than destroying the greenfield site he has come to love.

In the letter, he describes himself as a "temporary resident" of Ovingdean and warns the company he will use his "very strong connections" to prevent the plant being built there.

Speaking from Chicago, where he is filming a second series of American Idol, Simon said: "I am extremely concerned about these plans. It seems insane to consider destroying this beautiful countryside to build an ugly sewage plant.

"I enjoy walking my dog Prancy and my mother's Yorkshire terrier round the Downs when I visit.

"I am disgusted all that may be taken away and will do everything in my power to prevent it. I will even go down to Southern Water's office to discuss it face-to-face if I have to."

Simon's mum, Julie Cowell, has lived in Ovingdean for eight years and told him about plans for the sewage works about a month ago.

She said: "I was very surprised at how angry Simon felt about it. He went for a walk with the dogs recently and asked me about the proposal. When I told him he was absolutely appalled.

"The more we spoke about it, the more furious he became. He loves coming to Ovingdean and walking.

"He does not want to see this part of the world spoilt."

Simon has written a letter of support to the Campaign for Ovingdean Against Sewage Treatment (COAST).

Group chairman Robert Mojab said: "We are delighted such a high-profile person, who is practically a resident, has lent his support to our campaign."

The Ovingdean site is among others being considered by Southern Water. They include Shoreham Harbour; Black Rock and Kemp Town gasworks; Lower Sheepcote Valley; Upper Sheepcote Valley; Peacehaven East; Brookside Farm Tip, Newhaven; and North Quay, Newhaven.

Geoff Loader, communications manager at Southern Water, said: "Simon is one of 2,000 people to have written to us since we announced the eight short-listed sites and all the comments are being analysed.

"More than 1,500 people came to our public exhibition to find out more about the plans and we have continued to discuss the issue with individuals.

"Simon is welcome to speak to us on the matter further."