Martin Haworth, director of policy at the National Farmers’ Union, said: “We are not opposed to vaccination if it is advised as the best strategy by Defra.
“It would be a huge undertaking with some logistical difficulties, but nevertheless it is still an option in our armoury.”
In 2001, the union opposed the vaccination of animals against foot and mouth disease in favour of a controversial mass cull.
Patrick Holden, director of organic body the Soil Association, this week criticised the government for not holding stocks of vaccinations to protect poultry in the event of bird flu coming to the UK.
He said: “Vaccination is now the adopted method of control for foot and mouth. It should also play a key role in any strategy to control an outbreak of bird flu.”