Historians have voiced serious concerns over a plan to halt excavations at a world-famous Roman palace.

English Heritage wants to turn a field brimming with artefacts near Fishbourne Roman Palace, south of Chichester, into a scheduled ancient monument. But archaeologists fear this will either limit future excavations or stop them altogether.

Since 1995, the Sussex Archaeological Society has recorded 14,000 finds on the site, including part of a military sword scabbard that sheds new light on the Roman occupation.

Now talks are being held between English Heritage and the society.

English Heritage believes historic sites should be preserved so archaeologists of the future can excavate them using less damaging techniques.

Critics say the same argument could be applied 200 years from now, resulting in sites never being investigated.

John Manley, chief executive of the society, said: "Some may be wondering why a body such as English Heritage would want to stop the excavations. It comes down to preserving sites of national importance for posterity.

"There is no doubt our excavations have demonstrated there is highly significant archaeology to the east of the palace.

"The argument goes that current methods of excavation are destructive.

"Given the current general attitude of English Heritage towards excavations of scheduled ancient monuments, it seems unlikely that we will carry out research excavations again at Fishbourne in the foreseeable future."

David Rudkin, director of Fishbourne, said: "We would be disappointed if we could not continue but at the same time we recognise English Heritage does have a policy whereby sites of national importance are not excavated unless under threat of destruction. I am hoping we can reach some sort of compromise."

Fishbourne, renowned for its fine mosaics, was discovered by workmen digging a water main trench in 1960.

Further excavations revealed the site had developed from a military base at the time of the Roman invasion in AD43 to a sumptuous Palace by the end of the first century AD.

A spokesman for English Heritage said: "We believe that particular area is sufficiently important to merit scheduling and we are considering that.

"We do recognise the society has been undertaking valuable work there so our chief archaeologist is going down to Fishbourne in the New Year so they can meet to agree a strategy for further research and preservation of the site."