The number of adults working beyond the state retirement age almost doubled between 1993 and 2011, according to a new report from the Office for National Statistics.

There are now 1.4 million over 65 working even though they are eligible for a state pension, compared to 753,000 two decades ago. This increase has been attributed to people's improved health and wellbeing, as well as growing financial pressures and the need to build up more retirement savings.

The data revealed that approximately two-thirds of people who choose to stay in work after reaching retirement age do so on a part-time basis, with London and the south-east boasting the highest employment rate for older workers, while the north-east has the lowest.

Since 2010, the state pension age for women has been rising to match that of men and it will stand at 65 for both genders by 2018, before rising to 66 in 2020.

With the pension age rising and more people choosing to work longer so they can stay active and build up a greater savings pot, consumer group Which? has reminded people who do work on to make sure they defer any pensions if they will not need the income.

It is possible to boost private pension pots by carrying on in work, although it is always advisable to speak to your pension adviser so you know what exactly the options are.

In terms of state pensions, you can defer claiming them for as long as you like and the pension you receive will be based on the rates at that time, so the longer you leave it to start drawing your pension, the more you are likely to receive as a result of rate rises.

Deferring will also allow you to earn an increase in your state pension, at a rate of one per cent for every five weeks that you put off claiming.