03/03/2016 05:49 EST | Updated 03/04/2017 00:12 EST

Tentative labour deal reached between CUPE Local 79 and city

The union representing about 20,000 City of Toronto inside workers says it has accepted a tentative four-year

contract with the city.

The deal will next face a ratification vote by the union's 20,000 members represented by CUPE Local 79.

CUPE Local 79 president Tim Maguire said the deal was reached after "a very difficult round of negotiations."

He also said the union is recommending its members ratify the agreement.

"We believe we have secured the best possible collective agreements for our members, ensuring they will continue to be able to deliver the great services Toronto residents depend on," Maguire said in a news release issued early Thursday. 

Deal still faces ratification vote

Details of the deal will not be released until the ratification vote. 

Maguire is expected to provide more details at a news conference set for 10 a.m. ET. will live stream that news conference.

As negotiations reached an impasse in recent weeks, Local 79 members began a work-to-rule campaign, with some workers refusing to perform duties not specified in their job descriptions.

The union says part-time staff at the city's 10 long-term care facilities will have their contract sent to arbitration due to

outstanding issues. Those workers do not have the right to strike.

On Monday, Mayor John Tory said the city had issued what it called a "final offer" which Maguire rejected by saying it would create a "two-tier" system for contracting out public services.

The city posted highlights of its offer online, which included protections against contracting out for some workers in addition to a five per cent raise over four years.

CUPE Local 79 members include child-care workers, planners, cleaners and shelter nurses. A strike or lockout would have closed city-run daycares and many city offices.

Last month, outside city workers represented by CUPE Local 416 ratified a new contract with the city that includes protections against contracting out for some workers in addition to a five per cent raise over four years.