HALIFAX -- Nova Scotia's largest public sector union says conciliation talks with the province have failed and it is now filing for arbitration on behalf of 8,000 civil servants.

The Nova Scotia Government and General Employees Union said the province hadn't budged from any of the key issues included in its last offer, including a wage increase of 3.5 per cent over four years.

Union president Jason MacLean called the talks "frustrating" and said Wednesday that the goal is to reach a fair agreement "once the premier is removed from the bargaining table."

"I think the government is more about (union) capitulation," MacLean said in an interview.

"They have this stance and I think they can't understand why anybody would want to keep what they already have. It seemed to me that they weren't very prepared to get into this like we thought they would be."

MacLean said a major stumbling block is the government's intent to end a retirement payment known as the public service award.

He said the union's membership is adamant about retaining benefits won in previous bargaining attempts.

"It's absolutely paramount the public service award remains intact," said MacLean, while hinting at some flexibility.

"We can go out and replace it with something, but it has to be at equal value or near equal value. We are looking to maintain."

An arbitration hearing was originally scheduled for Tuesday and Wednesday with the province's labour board, but those were set aside after the sides recently agreed to one last attempt at conciliation.

The union said the government had agreed it wouldn't oppose the union's request for arbitration if the conciliation talks failed.

Premier Stephen McNeil had said in the past that he didn't want an "unelected third party" to determine what the government can afford to pay in any binding decision.

In a statement Wednesday, Labour Relations Minister Mark Furey expressed disappointment that both sides had agreed that the negotiations had reached an impasse.

"We appreciate the value, expertise and commitment of our public service employees, and respect their collective bargaining rights," said Furey. "We also understand that collective bargaining requires give and take, and we have been willing to negotiate a fair deal with the NSGEU, one that ensures the services Nova Scotians depend upon are sustainable."

"We'll take time to thoroughly consider our options."

The workers are employed across a range of government services including Service Nova Scotia, corrections, child welfare, the courts, and health and safety.

The membership rejected the government's contract offer in a vote held last December and have been without a new deal since March 31, 2015.