A £300 million redevelopment of the busiest hospital in Sussex has taken its next step.

Managers at the Royal Sussex County Hospital in Brighton want to give it a makeover by pulling down and replacing its two oldest buildings.

Brighton and Sussex University Hospitals NHS Trust, which runs the hospital, has now approved the outline business case for the plans.

The proposal has been sent to the South East Coast Strategic Health Authority for approval.

If the authority and the Department of Health agrees, the new look hospital could be up and running by 2013.

The aim is for the cost of the scheme to be met through central funding rather than a private finance scheme.

The redevelopment aims to transform the Royal Sussex into a major trauma centre for Sussex and the South East.

It will include a helipad so critically ill patients can be treated more quickly.

There are also plans to transfer the Hurstwood Park brain injuries unit from Haywards Heath to the site.

In a message to staff, trust chief executive Duncan Selbie said: “The Barry and Jubilee Buildings are over 180 and 130 years old respectively.

“Both were completed before X-ray was discovered and they are utterly inadequate for the provision of dignified, safe and modern patient care.

“They contain more than 200 beds for general and elderly medicine, cancer, HIV and infectious diseases.

“We are pouring good money after bad to maintain these buildings to even the most basic standards.

“The move of neurosciences to the Royal Sussex will enable major trauma for the south east to come to Brighton instead of London, and mean we can treat patients with the most difficult and complex conditions in a whole range of specialties much closer to their homes.”

The trust is working closely with Brighton and Hove City Council as it develops a planning application and work will be carried out in phases.

The development will also include underground car parking spaces to help cope with any increase in patients and visitors.