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.

One government official said surveillance efforts have been stepped up to monitor live birds for cases of infection, as well as mobilising groups led by the Royal Society for the Preservation of Birds to identify any dead animals that can be analysed for signs of infection.

However, planners remain confident that rapid identification and culling, combined with carefully monitoring in a 10km zone around any outbreak, should be able to prevent the spread of the virus, as illustrated by the apparent success of the same approach in France after a case of H5N1 was identified in domesticated poultry.

They are finalising advice in the event of such an outbreak, which is likely to call on farmers to bring livestock under cover to reduce the risk of infection, and to pet owners to keep cats inside and dogs on a leash.

The RSPB has been actively monitoring wild birds for signs of the disease since last year. But it maintains that the chances of the disease being brought to the UK by wild birds is very small. “It’s still regarded as a low risk,” an official said.

She said most migrating water birds, which are believed to be at the highest risk of the disease, were leaving the UK and the birds that were arriving for spring were mainly song birds, such as swallows and warblers, which were coming from areas – such as South Africa and west Africa – that had not been affected by the virus. Such birds do not frequent the wetland habitats that have been most associated with the disease in wild bird populations up to now.

Separately, the Association of British Insurers is set to issue guidance to employers stressing that they are unlikely to benefit from compensation for business disruption in the event of a human flu pandemic.

The ABI will warn that companies should prepare continuity plans because a pandemic is unlikely to be covered in the usual categories triggering business disruption payments such as earthquakes and floods.

However, it will also stress that life assurance contracts for individuals should cover a pandemic. Nearly 100 people around the world have been confirmed as dead from H5N1, and there have been no indications of a mutation in the virus to make it easily transmitted between humans – the precondition for a pandemic. Were that to occur, the government estimates up to 700,000 could die within the UK.