Flu has reached epidemic levels in some parts of the UK with the “Japanese” strain now dominant after the NHS failed to vaccinate against it, official figures show.

Latest data from Public Health England shows that cases of flu have risen by 150 per cent in two weeks, fuelling a “significant excess” of elderly deaths.

The statistics show that epidemic levels have already been reached in the city of York, with Herefordshire and north Somerset close behind.

Health officials said the current season is the worst for seven years. If trends continue, an epidemic will be declared across England within a fortnight.

GPs last night urged sufferers to stay at home, rather than adding to pressures on practices and fuelling the spread of the virus.