When Ronnie Corbett played Timothy Lumsden, the 40-something stay-at-home in Sorry!, it was only a sitcom.

But people are starting to ask whether life in Brighton and Hove is imitating art, or at least television, as rising house prices force more and more sons and daughters to continue living with their parents.

In short, they ask, are we about to become a city of Timothy Lumsdens?

House prices in the city are continuing to rise, with the average cost of flats or starter homes between £100,000 and £150,000, according to Brighton and Hove City Council figures.

To afford a mortgage at these levels typically requires an annual salary of more than £40,000 - beyond the range of many young people hoping to climb the first rung on the housing ladder.

And it is not just the young.

House prices in Brighton and Hove are about 13 per cent above the national average, while salaries are 9.5 per cent below. The average annual wage among all workers in the city is £19,770.

Marion Cunningham lives near Preston Park in Brighton. Her daughter, Nicola, 23, is among the thousands of young people caught by the inflated prices.

Marion blames the housing trap on the publicity over Brighton and Hove's new city status. She says the hype has attracted people from outside, particularly London, into the market, which has pushed up prices.

She said: "I am left wondering just what benefit the new status has been to the average Brightonian.

"There is certainly one section of our society to whom it has dealt a very cruel blow. They are the 20-somethings who are about to embark on buying their first home.

"Just what are our young people meant to do? Will we become a city where all our sons and daughters are still living at home aged 40 plus?"

Marion's daughter, together with boyfriend Dominic Higgins, has been looking for somewhere to buy since the start of the year.

The couple, like many others eager to stay because of the city's buzz, started saving for a deposit only to find that, by the time they had saved the planned amount, the figure they needed had shot up.

Dominic said: "We are fairly well paid. For some people on a normal salary in Brighton who are just starting out in life, it is ridiculous.

"They have done a good job raising the profile of Brighton and Hove but it's not much good if you can't afford to buy a home."

Renting in the private sector is hardly more welcoming to people on low incomes in a high cost city.

One and two-bed flats are currently let for between £500 and £800 a month.

John Holmstrom, of the Brighton Housing Trust, said: "That is a consequence of Brighton and Hove being successful. It makes it more expensive and difficult if you are on a low income.

"People who haven't got any connection locally, either family or someone they know through working here, are increasingly finding it impossible to live."

Public sector housing provision, a safety net for the private sector, is failing to cope, with a predicted shortfall in the city of some 27,000 low-cost homes in the next five years.

Almost 33,000 people and families who need a home will be unable to afford to buy during the same period, while there will be low cost homes for fewer than 6,000.

There are also an estimated 2,178 empty homes in the city, although the figure is notoriously difficult to gauge.

The homelessness charity Shelter argues for massive investment in low-cost homes, either council houses, or housing association homes, as a back-up to the private sector.

A spokesman said: "Shelter's largest concern is the fact there is very little alternative in many areas to buying. There needs to be more affordable housing made available.

"For many people they choose to buy when it is totally inappropriate.

"They push themselves to the very limit of what they can afford. They are then very susceptible to any change in income or interest rates, so they can be made homeless and have their home repossessed."

Pavilion MP David Lepper said housing would be his personal priority during Labour's second term.

He said: "I do sympathise because we still have a 26-year-old daughter living at home with us for much the same reason."

He said the Government had made some changes, such as tweaking housing benefit regulations for under-25s and making money available to help key workers such as teachers and nurses, but ministers had not done enough.

Among other changes he would like to see are rent regulation - especially important in a city where the amount of privately rented accommodation is double the national average - and scrapping the council tax rebate on second homes.

Crucially though, he said more should be done to raise wage levels and attract the type of jobs that pay higher salaries. This would enable local people to compete in the housing market.