Britain is gearing up for a possible outbreak of the lethal H5N1 flu virus in birds during April, and the still greater likelihood of infection this coming autumn, according to government officials.

Experts believe there is a risk of incidents in the coming weeks as wild birds return north from their winter migration, even though the UK is not within the main “fly away” zone, and a higher probability that cases will occur during the next migration southwards later in the year.