Primary care trusts will not be able to include any of Sainsbury’s 230 in-store pharmacies in their local plans to set up antiviral collection points.

The policy restricts the options for primary care trusts attempting to establish a network of convenient points for “flu friends” to pick up antiviral medicines such as Tamiflu on behalf of patients hit by the H1N1 pandemic.

Other supermarkets are making their in-store pharmacies available as collection points. A spokesman for Tesco said it was in discussions with PCTs and had “agreed to collection points at some of our pharmacies”.

A spokesman for Sainsbury’s said its policy was “long standing” and had been in effect since plans were developed to deal with a potential outbreak of avian flu.

He added that there had been no change in its policy and that the chain had not been asked to amend it by the Department of Health. The spokesman confirmed that “one or two pharmacies may have been approached” by PCTs asking if they could become collection points.

Asked why Sainsbury’s head office would not allow individual pharmacies to act in this way the spokesman said: “It would draw a lot of potentially unwell people into our stores. This is the sensible and prudent thing to do.”

In a statement, it said: “A supermarket, with thousands of daily visitors, is not a suitable collection point as it would lead to increased risk to shoppers and colleagues. This policy is in accordance with the government’s advice for those with flu to avoid public places.”

But a spokeswoman for Unison said the attitude of the company was in “stark contrast” to that of NHS staff. She added: “It’s the friend, not the ill person, who will collect the drugs”.

News of the chain’s refusal to act as a collection point in the pandemic follows controversy over the government’s relaxing of market entry rules in 2005 which allowed large and out-of-town shopping centres to open pharmacies.

The change had been recommended by the Office of Fair Trading but opposed by small high street pharmacists which claimed it could put them out of business. Almost one in three of Sainsbury’s 800 supermarkets have an in-store pharmacy.

A spokeswoman for high street chain Boots said its stores were “proactively working with PCTs” in their plans for antiviral distribution and a number of them had already taken on the role.