The population of the UK will surge by 4.4 million to reach 65 million by 2016, estimates suggest.

This increase is equivalent to an average annual rate of growth of 0.7 per cent, according to the Office for National Statistics (ONS), who made the projections.

Further ONS estimates suggest that the population will hit 70 million in 2028 and pass 71 million by 2031.

The ONS attributes the population growth to higher life expectancy rates and greater immigration.

The population of England is projected to rise by 8 per cent by 2016, that of Northern Ireland by 7 per cent and Wales by 5 per cent.

The increase for Scotland, where fertility and life expectancy levels are assumed to remain lower than in the rest of the UK, is expected to be just 3 per cent.

The figures also show that the UK has an aging population. The proportion of people aged 65 and over is projected to jump from 16 per cent in 2006 to 22 per cent by 2031.

"This is an inevitable consequence of the age structure of the population alive today, in particular the aging of the large numbers of people born after the Second World War and during the 1960s baby boom," said an ONS spokesperson.

"As a result, demographic support ratios will fall. In 2006, there were 3.3 people of working age for every person of state pensionable age.

"This ratio is projected to fall to 2.9 by 2031, taking into account the future changes to state pension age."