Employers trying to stockpile drugs to treat staff if Britain is hit by an influenza pandemic are being told to expect a minimum wait of two months as fresh supplies of the antiviral treatment are prioritised for the government rather than the private sector.

Concerns about avian flu have triggered a rush of inquiries to pharmaceutical and private healthcare companies from concerned employers. But worldwide shortages of the principal two antiviral drugs, which can be used to treat bird flu – Tamiflu and Relenza – mean employers are being warned they are unlikely to get supplies in time for an outbreak this winter. “It’s on a first come, first served basis and there’s a waiting list,” Roche, the manufacturer of Tamiflu, said.