Sick northern suburbs residents face an uncertain winter, with the emergency department at Bulli Hospital facing further closures.Patients have been diverted to Wollongong four times in the past two months as part of a strategy to centralise the region's depleted medical workforce at major hospitals during the busy flu season. Yesterday the health service confirmed more temporary shutdowns were likely, but denied it would close Bulli Hospital.Patients were being sent to Wollongong Hospital on a shift-by-shift basis, a South Eastern Sydney Illawarra Area Health Service spokeswoman said. "This falls in line with the strategy to treat our sickest patients in our largest hospitals. "It also means that we can concentrate our medical and nursing staff in our major hospitals that take ambulance presentations and where staff have the support services they need. "This strategy has been proven to work," she added."It's quite possible it (diversions) will happen again." A commission of inquiry into the health system last year recommended Bulli's emergency department be axed.Northern Illawarra Chamber of Commerce president Pauline Lacelles-Smith said the diversions gave weight to concerns the department would close permanently. "It always seems the first hospital where staff are taken from when they're needed elsewhere. They're obviously trying to downgrade the hospital and its services," she said.When the diversion is in place, those who turn up at Bulli emergency department are seen by a nurse. The seriously ill are taken by ambulance to Wollongong, while less urgent cases make their own way.Bulli's emergency department is expected to be fully functional during the day today and tomorrow, but staffing issues could force diversions as soon as tonight.Staffing shortages also loom tomorrow night and at the weekend. Opposition acting health spokeswoman Gladys Berejiklian said temporary shutdowns were part of the Government's "progressive downgrading" of Bulli. Most of the site's surgical services were relocated to Shellharbour Hospital earlier this year."The community has been rightly concerned for some time that the loss of many elective surgery procedures from Bulli to other hospitals is part of a Labor plan to close the facility altogether. The closure of the emergency department will only strengthen those suspicions," she said.The health service again denied that it had any closure plans."This position has been reaffirmed on numerous occasions to the community and the Illawarra Mercury and has been backed by the NSW health minister," a spokeswoman said.Health Minister John Della Bosca has said the emergency department's fate will be decided after a review of all state hospitals is completed later this year.A department spokesman backed the strategy put in place in the Illawarra, as did Minister for the Illawarra David Campbell."There have been people who have been making those (closure) allegations for probably a decade and they haven't come to fruition," Mr Campbell said.