HALIFAX -- The union representing nurses in the Halifax area has given official strike notice for just after midnight on Thursday.

Holly Fraughton, a spokeswoman for the Nova Scotia Government and General Employees Union, says the formal walkout notice for the 2,400 nurses was served today.

The union and the Capital District Health Authority were in talks with a mediator.

Capital Health spokesman John Gillis says the two sides were still discussing the union's latest offer on emergency staffing.

He also says that as the strike deadline approaches, the hospital is continuing to cancel surgeries and transfer patients to hospitals outside of Halifax.

Gillis expects the number of acute care beds at the district's hospitals will fall from 634 down to 432 if there is a strike, a decrease of 37 per cent.

The key sticking point in the dispute is a demand from the union to increase nurse-to-patient ratios, something it says would improve patient safety.

The health authority has said there is no evidence that mandated ratios guarantee better safety.