The city and union reached a tentative agreement on Thursday to end Ottawa's transit strike.

The City of Ottawa and Amalgamated Transit Union Local 279 have both agreed to send their dispute to binding arbitration with no conditions on all outstanding issues, Mayor Larry O'Brien said at a news conference Thursday, the 51st day of the strike.

"I'm delighted to say that we reached a tentative agreement and … I am happy about this," O'Brien told CBC News.

The strike will officially end once city council and the union's membership both ratify the deal. Council has a special meeting scheduled for 11 a.m. Friday.

There was no official word yet on when the first transit buses will be back on the road.

Ottawa Coun. Alex Cullen said residents shouldn't expect buses to be back on the road immediately. Transit services will resume late next week at the earliest, Cullen said. More details are expected to be released Friday, he said.

Once council and the union ratify the agreement, an arbitrator is expected to come up with a three-year contract that deals with wages, benefits, sick leave and contracting out for the approximately 2,300 transit drivers, dispatchers and maintenance workers represented by ATU 279.

After the deal was announced, the House of Commons cancelled an emergency debate scheduled for 6:30 p.m. ET to consider back-to-work legislation for the striking transit workers.

Transport Minister John Baird, MP for the riding of Ottawa-West Nepean, said if either party doesn't ratify the agreement, the back-to-work legislation will be introduced immediately.

"We still have it on the order paper in case something falls," he said.

Labour Minister Rona Ambrose said Thursday that her announcement the previous day that she would consider the legislation provided enough pressure to end the strike.

"It did provide enough pressure on both parties to have them get back to the table and come up with an agreement together, which is, of course, within the … best interest of the parties, of the government, the people of Ottawa," Ambrose said.

O'Brien said when the federal government began to move forward with the legislation it was obvious that the strike was over.

"It was inevitable and it was time to start talking about how quickly we can speed that process up," said the mayor.

O'Brien said as they go into binding arbitration, the city and the union are still very far apart on scheduling, raises, bonuses and benefits.

"I'm comfortable that the arbitration process will lead to a sound and responsible solution for this strike," he said.

Members of ATU 279 walked off the job on Dec. 10.

On Jan. 8, union members voted 75 per cent against an offer issued by the city on Dec. 23. Ambrose had ordered them to vote on the offer after a request from the City of Ottawa.

Afterward, both sides proposed binding arbitration, but were unable to agree on the conditions.

On Jan. 24, city council agreed to revised bargaining terms, and talks resumed briefly before breaking off again on Jan. 27.

On Jan. 28, the Canada Industrial Relations Board ruled that the transit strike did not pose an immediate or serious danger to public health and safety, and essential-services agreements between the city and the union did not need to be revised to maintain a level of regular transit service.

The board had been asked by the labour minister to look at the agreements and had made its decision based on more than 3,000 submissions from the public and the two sides in the dispute.

"I guess everyone is going to feel like a bit of a loser," said Randy Graham, an international vice-president with the Amalgamated Transit Union.

Graham said the union would have rather had a negotiated settlement but that going to binding arbitration is in the best interest of everyone.

"It is time to move on," he said.

NDP MP Paul Dewar, who represents Ottawa-Centre, said it is good that the situation is being dealt with at a local level.

Dewar urged both sides and local residents to continue mending fences and reconcile as the city returns to its normal routine.