By Jane Mower BBC News, London

Sleeping on a friend's floor for 18 months while flat-hunting was not what Ian Donoghue had in mind after returning from a gap year in Australia.

A bright future for key workers?

Settling into a job and buying a home were his priorities, but faced with soaring house prices he realised his friend's generosity was a lifeline.

Earning �17,000 a year working for a HIV and Aids charity, an unrealistic �68,000 property was his limit.

He was faced with the prospect of leaving his job or leaving London.

That was until a shared ownership scheme, designed to help people on low incomes, helped him buy what is now his home.

He was able to buy a 50% share in a �128,000, one-bedroom flat, in Earls Court, west London.

This costs him �180 a month for the mortgage and �650 a month for rent on the other half of the property.

Similar properties in the area are now selling for �230,000.

Travel costs

He said: "It signalled the end of an unhappy time for me and it gave me that foot on the ladder."

Mr Donoghue, now 36 and working for the NHS, says such schemes are "crucial" to keep key workers in public services and in London.

"Through my work, particularly at the moment, we are constantly recruiting clinical staff and we are constantly losing staff due to this very issue," he said.

"They are attracted to London because people want to experience the London life but after a couple of years they come to the point where they are in a relationship or they want to buy somewhere.

"They soon realise that in order to do this they have to leave the NHS or leave London."

I felt my selection criteria for property was very normal, I wasn't looking for anything palatial, just something solid, warm and comfortable Ian Donoghue

After his gap year Mr Donoghue returned to Hammersmith, west London, where he had grown up and realised fairly quickly "that things were grim".

"I wanted to stay in the area as I had family connections and community attachments but I couldn't afford anything there.

"I started looking further out of London, in different zones and different parts of London, but the further I went out the greater the travel costs were.

"It got to the point where the only way I could afford to buy somewhere was by living in Luton."

He approached the council but was advised to make "alternative arrangements" due to the demand on housing in the borough.

Shared ownership

"I was faced with finding a job in the private sector to earn more money or moving out of London altogether," he said.

"I felt my selection criteria for property was very normal, I wasn't looking for anything palatial, just something solid, warm and comfortable."

When he saw an advert for shared ownership housing in the same road he was renting in he jumped at the chance.

"Without this I would have been one of the many who have to leave London for financial reasons and head for other parts of the country."