The controversial decision on whether to move Brighton's Nigel Porter unit to Haywards Heath is due to be made on September 27.

The proposal has sparked outrage. There was no argument that the Nigel Porter Unit for Breast Care at the Royal Sussex County Hospital site had outgrown its home.

The unit was assessed by the Government and was failing to treat patients within a two-week period of visiting their GP.

Health bosses blamed the lack of space for the failure to meet targets, while others said the unit needed a second breast cancer surgeon.

Stuart Welling, chief executive of the former Brighton Health Care NHS Trust, which runs breast cancer services in the city, said the unit had experienced a 40 per cent increase in referrals over the previous five years.

Whatever the cause, it was agreed a new, larger home was needed, particularly if the unit was to meet new targets set by the Government to screen women up to the age of 70.

Health bosses told a public meeting the answer lay at the Princess Royal Hospital in Haywards Heath, which was run by the Mid Sussex NHS Trust, shortly to be merged with the Brighton-based NHS trust.

The newly-formed Brighton and Sussex University Hospitals Trust wanted to centralise some of the health services between the hospitals, particularly as Mid Sussex had a £2.6 million overspend.

Health chiefs agreed there was nowhere suitable for the unit in Brighton, although Mr Welling admitted in an ideal world it would remain in the city.

It was suggested a building at the Princess Royal site could house a new unit at a minimal cost.

Both health experts and even the Government's own Cancer Plan published in September 2000 recognised all services related to cancer treatment, such as radiotherapy and chemotherapy, should be on one site, as they were in Brighton.

Despite that warning, the trust continued with plans to move into the building in Haywards Heath at a cost of just £3 million.

Architects then discovered the building in Haywards Heath was not suitable to house the unit after all and it was agreed a new unit would have to be built at a cost of about £7 million.

Campaigners desperate for the unit to remain in the city identified a former children's home in Brighton, owned by the trust, which could be a possible site for the new unit.

Rosaz House in Bristol Gate was near to the Royal Sussex's chemotherapy and radiotherapy services. The proposed site was also backed by Government health minister Hazel Blears.

On July 3, city councillors voted unanimously to grant outline planning permission for a new breast cancer unit at Rosaz House.

If it becomes the chosen location, Rosaz House would be demolished and replaced by a four-storey building with one of the floors sunk into the ground, providing enough space for the 2,500 women expected to use its facilities every year.

A 17-space parking area would be moved underneath the building so no parking would be lost.

A five-page report into the plan said: "As public transport provision and infrastructure is already to a very high standard in the vicinity and the residents parking scheme should prevent additional parking problems being caused, the traffic impact of the proposal is considered acceptable."

The report concluded: "A medical block of the size proposed can be accommodated on this site without unacceptable disbenefits to the amenities of neighbouring residents or to the character of the area."

Although Rosaz House would be the more expensive option at £13 million, Mr Welling admitted it would be easier to attract cash from the private finance sector to a project of this size than to one costing less than £10 million.

The Brighton proposal was also expected to have an easier passage through the planning process.

City councillor Jayne Bennett said: "The Brighton application went straight through whereas the Haywards Heath bid was much more involved."

In the first planning step for outline permission, the trust was forced to lodge two applications for Haywards Heath: A three-storey building taking up less of the vital car parking spaces at the hospital and a wider two-storey building, which would take up more parking spaces.

Although both applications were granted outline permission, neither received unanimous support.

Mid Sussex councillor Jim Beacon said: "I suspect we will give the application for the wrong reasons and we will then have a fight with Brighton, which we will not win."

A 16-page report listed concerns about the impact on a nearby Grade II-listed water tower.

It also said a travel plan should be prepared and submitted prior to any occupation of a new unit.

West Sussex County Council has also insisted the trust should provide replacement parking for any spaces lost to a new unit.

Consultants said more than 8,000 people would travel to the Haywards Heath unit a year and many of these journeys would be by car due to poor public transport links.

Des Turner, MP for Brighton Kemp Town, insisted Rosaz House would cause the least disruption to patients across Sussex.

He said: "There are already breast care services available at the Princess Royal Hospital so there is no question of Mid Sussex women being disadvantaged if the Nigel Porter Unit is replaced at the Royal Sussex."