Kippers - or Kids In Parents' Pockets Eroding Retirement Savings - is the new buzzword for children who just will not leave home.

Millions of 20 and 30-somethings are still living with their parents, many having moved back after university against a backdrop of high property prices and later marriages.

Forced with a stark choice of either renting or living with their parents and saving a bit of cash, more children are choosing the latter.

Research by the Prudential found 60 per cent of over-18s living at home had jobs but still lived rent free.

In the South-East, 28 per cent of children living at home are not working, 46 per cent are in full-time employment and 63 per cent of parents do not charge any rent.

Even if they do, the average is £73 per month, which is significantly lower than the rent for a one-bedroom flat or a room in a house.

Pub assistant Claire Reuter, 22, is living with her mother in Uckfield while her partner Mitch Hazelden, 29, who runs his own bakery business, is living with his father.

The pair desperately want to buy a home together but cannot afford it so their only option is to stay with their families and save up.

Miss Reuter said: "We can't get a mortgage. I have looked into council accommodation but they have very long waiting lists.

"For financial reasons it is much easier to stay at home.

"I do pay rent to my mum but it is a lot less than I would if I were renting privately.

"I would like to get somewhere as soon as possible but my boyfriend is in the same situation.

"We are trying to save. We thought about renting but it is so expensive. What we would like to do is part-rent-part-buy through a housing association.

"A house came up last week and we needed to pay 50 per cent which would mean a mortgage of £80,000 but we could only get £60,000.

"The way it's going it will be quite a few years before we move out yet."

Mary Cotter, 33, moved back to her parents' home in Brighton - 15 years after leaving at the age of 18 to live in London.

She returned after splitting up with her boyfriend of ten years following a year travelling the world together.

In 1999, they bought a house in Greenwich, which they decided to rent out during their 12-month trip.

They decided to continue to do so on their return in June this year and Miss Cotter realised moving back home with her parents, John and Valerie, was the best option.

She pays them a small rent, which has given her time to save up but she has not quite got round to moving out yet.

The research found that a staggering £20.24 billion is paid out annually by parents to support their adult offspring, leaving them with the prospect of having less savings in retirement.

Up to two million parents have children aged over 30 still living with them and up to one million have children who are 36 or older living at home.

A further 606,000 have children aged between 27 and 29 living at home.

Four out of ten parents admit to helping their adult children financially even when they have left home.

Angus MacIver, director of research at Prudential, said: "The findings may come as a rude shock to parents who expect their kids to be out the door when they turn 18.

"These days parents may be stuck with them for much longer.

"While this may not be a problem in itself, the real worry is how much these kids cost - and the extent to which they eat into parents' retirement savings.

"Whether our kids leave home at 18, 20 or 30 years of age, families need to plan ahead for every eventuality.

"Not only do they need to plan to help their children, they also need to balance that with the need to plan their own retirement.

"Kicking off a savings scheme or pension as early as possible for their kids is an excellent start."

A spokeswoman for Brighton and Hove City Council said: "Our priority is housing families.

"People on the housing register who have adult sons and daughters living with them have asked to be rehoused as families.

"There are now 79 families either looking for accommodation or who are on the council housing transfer lists."