Britain is projecting more than 100,000 new cases a day of the H1N1 flu by the end of August and will change the way it deals with the virus, according to the government.

"We could see over 100,000 cases per day by the end of next month - though I stress this is only a projection," health minister Andy Burnham told Parliament.

He said the number of confirmed cases of the virus known as swine flu is doubling every week, putting pressure on health services.

"We have always known it would be impossible to contain the virus indefinitely and that at some point we would have to move away from containment to treating the increasing numbers falling ill," he said.

The World Health Organisation declared on June 11 that the outbreak of the virus was a pandemic. More than 77,000 people have been infected worldwide.

Most people who have caught the infection have only suffered mild symptoms, but in a small minority it has proven more severe, with three deaths in Britain so far.

The first doses of a pandemic flu vaccine would arrive in Britain by the end of next month, with 60 million doses available by the end of the year, enough for 30 million people, or about half the population.

Health officials will make it a priority to provide antiviral medications to the most vulnerable, and will abandon efforts to trace people who have been in contact with flu sufferers.

Health authorities also will no longer compile daily updates on the number of new cases, with estimates of the general spread being issued instead.

There are 7,447 confirmed H1N1 flu cases in Britain, with infections spreading fastest in the southwest, the east, the east Midlands and in London, which all saw more than a threefold increase over the past week.