The Government's Chief Scientific Adviser has predicted bird flu will arrive in the UK and remain for at least five years.
Professor Sir David King said he feared the disease could possibly become "endemic" in Britain.
Sir David told the BBC: "I would anticipate that avian flu will arrive at some point in the UK.
"We also have to anticipate that it will be here for five years plus. We are talking about the possibility of this disease being endemic here in the UK as it did in China. It is a long-term factor."
He had earlier ruled out the use of the currently available bird flu vaccines in the event of a UK outbreak, but conceded they may have to be used if the outbreak was widespread.
"The Chinese have adopted the position of mass vaccination, and if it became so widespread here we might have to go down that route even with the vaccination not being very good," he said.
Sir David added that he expected bird flu to reach UK shores in months, rather than days or weeks, due to the pattern of migratory paths.
Yesterday, he said the existing H5N1 inoculation would mask signs of the virus in birds but not prevent its spread.
Rare breeds of birds kept in zoos would be the only cases where vaccines would be feasible. The inoculation of organic or free range birds would not be recommended.
Sir David said the UK was currently monitoring the development in China of a new vaccine against the H5N1 strain of avian flu.
His comments followed his appearance at the National Farmers' Union conference in Birmingham yesterday.
He told the conference that people involved in carrying out a cull would be at the greatest risk from avian flu in the event of a UK outbreak. Bird flu does not pose a risk to consumers, he added.
Environment Minister Margaret Beckett earlier told journalists at the NFU conference that the Government was keeping the use of bird vaccines under review.
NFU president Tim Bennett said the union would continue to review the avian flu contingency plan.
"Certainly my poultry keepers are concerned about the fact that it is now in France and they are asking me if there is any more we can do in terms of bio-security and vaccination," he said.
"If the scientists recommend vaccination we will go with vaccination. That is why we must make sure, if that is what is recommended, we can actually do it."
Commercial poultry owners who keep 50 birds or more have until today to register their flocks on Defra's new national poultry register.
Keepers with fewer than 50 birds are not required to register at present but may do so voluntarily after today if they wish.Reuse content