An insurance wrangle could see some GPs refusing to work if swine flu spreads across the UK, the doctors' union warned today.

The British Medical Association (BMA) said doctors were worried about being sued over the care they provided if infections became widespread, and a lack of death-in-service cover.

Dr Dean Marshall, one of the BMA's negotiators on flu planning, told the BBC: "Doctors will be putting their lives on the line and it is only right they can feel assured they are properly covered if anything goes wrong.

"We don't want to be going into it with GPs feeling unsure where they stand. Doctors are only human and some will not want to go on the front line."

Hospital doctors are covered by NHS indemnity insurance, meaning they are protected if sued over the care they provide.

But GPs being effectively self-employed have to make their own insurance arrangements. Some fear this may not cover them adequately during a serious flu outbreak.

Dr Marshall said: "The problem is that the current cover expects GPs to act in a certain way.

"For example, if someone has a heart attack we should send them to hospital, but during the pandemic hospitals could be full and this may not be possible.

"Our fear is that later on people may sue us."

GPs also fear that if they were to die on a non-work day, their families would not be entitled to death-in-service payment.

Dr Marshall said: "A locum could die at the weekend and their family might not get a payout. That is not fair and could make some think twice about helping out."

Andrew Clapperton, from NHS Employers, said it was up to GPs to arrange their own indemnity insurance cover.

He added: "We are currently in discussion with both the BMA and the Department of Health to establish how we might best achieve this solution."