Modern-day warships, some which have helped change the course of history, are being left to rot as they have no protection in law.

But now the government is being urged to allow naval vessels to become 'listed' like buildings.

Martyn Heighton, the former head of the Mary Rose Trust and now in charge at National Historic Ships, has written to minister Margaret Hodge urging her to amend a bill currently going through Parliament.

It comes as HMS Intrepid, which helped liberate the Falklands Islands, is to leave Portsmouth and be broken up for scrap, despite a nine-year campaign to save her.

Mr Heighton said: 'Models, plans, or photographs are not adequate substitutes for the real thing.

'Although we accept that practical considerations limit the number of vessels that can be preserved, it is equally the case that these historic vessels play an essential role in expressing our national story.'

Campaigners say while HMS Victory, HMS Warrior and Mary Rose are kept for future generations to see at Portsmouth's historic dockyard, 20th century vessels are simply being scrapped.

Our campaign aims to persuade the Department of Culture, Media and Sport to include ships in the Heritage Protection Bill, before it is debated in the autumn.

Mr Heighton's experience with the Mary Rose Trust and his position with National Historic Ships is sure to carry weight at Westminster. As part of his job he reports directly to the secretary of state on ship preservation and funding priorities.

And the Save Our Ships campaign has already received backing from senior heritage figures.

Commander Ken Jones, commanding officer of HMS Warrior and a member of Portsmouth dockyard's heritage executive group, said: 'I think the principle of saving ships and bringing them here is a good one.

'There will always be restrictions of cost but it is right that we should do the best we can to ensure visitors to Portsmouth have a full picture of our history.'

A spokesman for the Department of Culture, Media and Sport said Mr Heighton's letter had been received and would be taken on board.

He said: 'We recognise that there are unresolved issues with regard to ships on the National Register of Historic Vessels and are happy to continue dialogue with the advisory committee, national historic ships to assess the specific needs of these assets.'