GOVERNMENT ministers and bird experts joined forces yesterday to appeal for calm over fears that bird flu is on its way to the UK.

But the Government acknowledged there was a higher risk of the virus coming to Britain after a duck in France was confirmed as being infected with the lethal H5N1 strain.

Ministers said yesterday that tests on nine swans found dead at sites across the country, including one in Thirsk, North Yorkshire, had proved negative.

Animal Health Minister Ben Bradshaw said birds would only be housed if there was an outbreak in this country, but added: "We are certainly thinking about it, and poultry keepers are ready to do it within 24 hours if we give the order."

Some North-East farmers have started taking precautions, including David Maughan, who has installed disinfectant footbaths and restricted access to his farm, near Staindrop, County Durham. Mr Maughan, who has 16,000 free range hens, said he thought a mass vaccination programme was not the answer.

National Farmers' Union president Tim Bennett urged consumers to continue buying and eating British poultry.

David Hirst, the RSPB's North-East information officer, said most of the birds that migrated to the region over the winter were from Scandinavia, Iceland and Greenland, rather than Europe.

He added: "Where H5N1 is infecting people, it is people who have been in close contact with domestic poultry and people who have been working around poultry.

"I think we need to keep that in perspective."

The Wildfowl and Wetlands Trust, which runs a centre in Washington, is advising the Department for the Environment and Rural Affairs and helping to test wild birds for H5N1 as part of the European surveillance programme.

* The Tower of London has decided to keep its six ravens in aviaries indoors to protect them from bird flu.