Schemes could also be made more flexible as people are being put off saving anything at all by the "stark choice" they face of either locking their money out of reach or not taking out a pension, Dr Ros Altmann said.

Speaking as the Government prepares to begin its landmark scheme to automatically enrol up to 10 million people into pensions from next month, Dr Altmann said that much of the language used around pensions was "alien" to many people.

She said: "I would like to find a new word for pension – lifetime savings or retirement savings – something that does not have negative connotations."

She argued that people often associated the word "pension" with scandals and disappointments, or something which was of relevance to older people only. Dr Altmann said pensions were seen as "quite frightening" by many people, and attaching a mechanism to help workers take money out when they needed it could help to fire up people's imaginations, especially those of the younger generation.

She said: "For me, the most important thing is to get people into the habit of saving. Pensions are just one product."

Dr Altmann raised concerns that some people such as those with student debt or who were planning to buy their first home may not be saving anything at all towards their later years because they were put off by the idea that their money would be locked away. She said that people could be encouraged to save more if pensions were made more flexible.

She suggested schemes could allow people to have access to some of their savings at times in their life when they were facing financial pressures and needed some "rainy day money".

The boss of the over-50s group said in January that pensions in their current form were "past their sell-by date", and had previously raised the idea that employer contributions could be used to help repay student loans for younger staff, who could then save for a pension later in life.

From October 1 the largest employers must place eligible employees into schemes, with smaller firms gradually being enrolled in a staging process which will end in 2018.

The Government is introducing various measures aimed at making pension saving more simple and attractive to people.

Further evidence of the pensions saving crisis was seen earlier this year when Office for National Statistics figures showed the proportion of people in a workplace pension had fallen below half for the first time in at least 15 years.