HEALTH Secretary Andy Burnham sought to play down his claim that the UK could have 100,000 new cases of swine flu every day as soon as next month.

Mr Burnham made the startling claim during a Commons statement to MPs when he also announced changes to the way the NHS deals with the virus.

Later he told reporters that the figure was "only a possibility" and urged people to be calm.

The figure has been produced by mathematicians who modelled the current growth in swine flu cases across the country.

They concluded that the rate of infection is effectively doubling every week and, if that rate continues, 100,000 people a day would be falling ill by August.

However, there is evidence to suggest that the virus will not be able to replicate as well in the current hot summer weather - and there are hopes the numbers will stall for a few weeks.

The Chief Medical Officer Sir Liam Donaldson said the virus was now so widespread that efforts to contain it - by issuing anti-viral drugs to sufferers and their close family - were no longer practical.

Instead, the country will now move to the "mitigation phase" of pandemic planning, treating sufferers only.

Fewer people will be swabbed to see if they really do have pandemic flu, because the NHS does not have the capacity to cope with tens of thousands of samples.

Instead, doctors will make a clinical judgement and prescribe drugs as they see fit.

In many cases, sufferers with a mild dose will be told to stay at home in bed and ride the symptoms out with the help of drugs like Tamiflu. If GPs are overwhelmed they have permission to prescribe anti-virals only to the seriously ill.

So far around 4,000 cases of pandemic flu have been diagnosed in the UK and three people have died.

The first batches of pandemic flu vaccine are expected in August and by December the UK's stockpile will be around 60 million doses - enough for half the population.

However, Sir Liam said the decision to administer two vaccinations had been taken when scientists expected a bird flu pandemic.

In the case of wine flu he said only one jab may be needed - helping stretch the vaccine further and making it possible to innoculate the entire population sooner.