A pair of peregrine falcons could disappear from a quarry site if plans to landscape the area go ahead.

The claim was made at a public inquiry into plans to transform the old cement works at Upper Beeding, near Horsham.

Jonathan Clay, representing developers Callstone, said Horsham District Council's plans could lead to the loss of the protected birds.

The birds, which nest in the vicinity, are one of only four breeding pairs of peregrine falcons in West Sussex.

Mr Clay said the plans also posed a threat to ravens at the site, which bred last year - the county's first recorded raven breeding since 1945.

The inquiry, which began on Tuesday, is investigating Callstone's proposals for the derelict Blue Circle Cement works. These include a business park, hotel, restaurant and 84 houses.

Horsham and Adur district councils object to the scale of the development and believe the houses are not necessary.

Horsham council has proposed a more complete restoration of the quarry cliffs, which it says are part of an Area of Outstanding Natural Beauty.

The alternative treatment, presented by Hankinson Duckett Associates (HDA) on behalf of the council, would involve building shoulders of land by the high quarry walls and flattening the bottom to provide a "slope profile typical of chalk downland landscape".

In his cross-examination of Tony Stevens, head of planning at Horsham, Mr Clay said there was a conflict between restoring the land and protecting the birds.

He said: "The problem with your scheme is the potential loss of protected species.

"It comes to a choice - change your policy to get rid of the cliffs or destroy the birds' habitat."

Mr Stevens said: "Loss of the protected species is not our overriding concern. It is an important consideration but I don't believe there is necessarily a conflict."

A report by Colin Shawyer, an ecologist and bird of prey specialist, on behalf of Callstone claimed the council's proposal would render the Adur Valley Park an unsuitable habitat for both the falcons and ravens, with the probable outcome that both species would desert the site.

He said: "Callstone's landscape proposal, on the other hand, provides good opportunities for successful migration for peregrine, raven and barn owl because it retains all of the habitat features necessary for these birds."

The report also criticised HDA's proposed timings for removing the earth, scheduled between April and October, since the period March to August was an important nesting time for peregrine falcons.

The inquiry is being held at the Steyning Centre in Steyning and is due to last until the end of the month.