Even before the release of the latest figures, government ministers had warned that the pressures created by an older population "posed as big a threat to the country as climate change".

The ONS report points out that:

• Over the past 25 years the percentage of Britain’s population aged 65 and over has increased by 1.5 million;

• The fastest growing age group has been been 85-and-over group –now referred to as the "oldest old". This group has doubled to 1.3 million since the early ’80s;

• By 2033 the number of people aged 85 and over is projected to more than double again to reach 3.2 million. It will grow to will account for five per cent of the total population;

• The average age of the UK population is increasing from 35 years in 1983 to 39 years in 2008, with average ages expected to reach 40 by 2034.

The head of public policy at Age Concern and Help the Aged, Mr Andrew Harrop, told the London Daily Telegraph that too little was being done to prepare for the crisis that was looming.

"The growth of an older population will mean significant challenges for policy makers in terms of funding and investing in the sort of services which an ageing society will rely on," Mr Harrop said.

"There is no excuse for not planning ahead to ensure that health, care, pension and other services are able to meet the needs of an ageing population."

Part of the expected growth in the aged population will be a huge growth in the number "supercentenarians" in Britain – those aged over 110 years.

The ONS says that while the number of people in the age group has remained relatively constant, they will soar over the next 25 years.

It says an increasing proportion of these oldest people will be men: "Although in the past there have been few male supercentenarians, it is projected that nearly 30 per cent of supercentenarians in 2034 will be male."

A report in the UK Express noted that the combination of the ageing of the population and the impact of the current recession was resulting in an increasing number of people continuing to work beyond the age of 65.