Designers plan to create an Italian-style quarter with covered walkways, fashionable apartments and chic shopping arcades in the heart of Brighton and Hove.

The historic site in The Lanes would be stretched to include a maze of storage sheds and buildings hidden behind the post office in Ship Street.

At present the only occupants of some of the empty buildings are pigeons.

Architects Alan Phillips Associates aim to breathe new life into the area, fusing new designs with the listed buildings, which give the district so much of its character.

Pedestrian pathways would weave through the site, creating a network of new city links, which would lead into open areas, arcades and apartments over the shops.

The architects say they want to give a new "Lanes quarter" back to the city, creating distinctive contemporary buildings which would fit in well with the old historic feel of the area.

The designs are among several being studied by the Post Office prior to a planning application being submitted to Brighton and Hove City Council.

The Post Office is selling its main site in Ship Street, including the buildings behind, and opening a new office next door so it retains a modern commercial headquarters in the city centre.

The Alan Phillips plan is on a shortlist of proposals for the site.

It would involve creating new passageways linking Ship Street with North Street.

There would also be a long walkway at the sea end, stretching from Meeting House Lane to Ship Street.

It would create a north-west corner of The Lanes and increase the variety of speciality shops, cafes and bars.

Other proposals for probably the biggest undeveloped prime shopping site in the city centre are believed to include transforming the existing post office into a department store.

The House of Fraser Group, which runs Army and Navy and House of Fraser stores, is keen to move into Brighton and believes the post office site would be ideal for a new outlet.

The Post Office is studying at least four schemes for the site but declined to reveal details of them.

The Alan Phillips scheme was put forward after consultations with planners and conservationists.

It is backed by the London-based Grainger Trust.

Several storage sheds would be removed but it is proposed to keep office buildings behind the post office, which are subject to conservation orders.

They would be transformed into flats and houses, with shops at ground level.

The Ship Street entrance to the "New Lanes" would be through a colonnade created by opening up the existing frontage of the post office, subject to conservation orders.

Alan Phillips - who is also behind plans for a designer island in the sea between the Palace Pier and West Pier - said: "Few people realise how large the area behind the post office is.

"It is one of the last remaining sites in the heart of this historic shopping area yet to be developed.

"It was certainly an eye-opener for me when I saw what was there.

"Some of the buildings are only inhabited by pigeons.

"One of the sheds was so infested with birds we could not survey it properly.

"This scheme would open up the north-west corner of The Lanes, greatly expand the area and ensure The Lanes remains a unique and thriving part of Brighton."

A city council spokeswoman said the authority would not become involved in the project until a planning application was submitted.

She said: "The Post Office invited developers to submit tenders by last Friday.

"Agents will then draw up a shortlist of schemes and they will decide which one to submit.

"We would like to see a mixture of retail and housing, of which 40 per cent would be low-cost housing.

"It is a very big site and we want it to be a quality development."