HALIFAX -- Nova Scotia Health Minister Dave Wilson said Thursday he is troubled by the possibility of a strike by the province's 800 paramedics on Saturday but is optimistic a resolution can be reached before then.

"I'm extremely concerned about the impact a potential strike from paramedics will have on Nova Scotians," Wilson said.

Wilson, himself a former paramedic, said he is hopeful that the union that represents the paramedics and their employer can come to an agreement to avert a strike now that a mediator has been appointed.

He said the provincial government has contingency plans in place with Nova Scotia's district health authorities, though he did not elaborate on what those were.

The government named John Clarke, a St. John's, N.L., arbitrator and lawyer, to mediate the contract talks between the International Union of Operating Engineers, Local 727, and Emergency Medical Care Inc.

The union has said that outstanding issues include wages and a demand for defined-benefit pensions instead of defined-contribution plans. It has also expressed its desire for a standard three-year deal instead of a five-year contract as suggested by the employer.

Emergency Medical Care has said it is committed to reaching an agreement and will leave discussion of the union's demands at the bargaining table.

In early April, the union's bargaining committee recommended acceptance of a tentative deal, but the membership rejected it last month.

The paramedics, who will be in a legal strike position as of Saturday, have been without a contract since 2011.

When the province's paramedics walked off the job in October 1999, company managers stepped in to keep the service operating. But the strike didn't last long. The paramedics were legislated back to work after 18 hours.