Officials are proposing up to a sixfold increase in the UK's stockpile of antiviral drugs as they reinforce preparations against a possible flu pandemic in the coming months.

Based on computer simulations of the likely spread of the virus, experts believe it may be worth increasing stocks of the drug Tamiflu, made by Roche, the Swiss-based pharmaceutical group, from the current 14.5m courses to 60m-90m, or up to one-and-a-half packets for every UK resident.