Ontario's correctional workers have given up their right to strike in the latest round of contract negotiations with the government.

The Ontario Public Service Employees Union and the government reached an agreement early Saturday morning after a meeting with a mediator.

As part of the negotiations, the union says corrections workers have been declared an "essential service," meaning they will no longer have the right to strike, and future bargaining disputes will be determined by binding arbitration.

The workers, including 6,000 jail guards and probation officers, had threatened to go on strike on Sunday if a deal had not been reached.

The union had hoped that correctional workers' salaries would increase to match those of first responders like firefighters and police officers when they gave up their right to strike, but this agreement doesn't touch on wages. That issue will be determined by an arbitrator in the coming months.

The workers, whose last contract expired in 2014, rejected a previous tentative agreement.

Another part of the deal is a commitment to lift a long-standing hiring freeze and hire at least 25 new probation and parole officers.

Thomas said this development is "huge," although the union originally wanted 100 new probation officers, and hundreds more corrections officers and jail guards.

He added the province has not agreed to hire a specific number of corrections officers.

"Of course we would have liked a lot more, but we took what we could from the employer," said Tom O'Neill, chair of the correctional bargaining team.

"It didn't happen overnight, and it's not going to be cured overnight, but we're definitely moving in the right direction.'

The government said the settlement is consistent with its fiscal plan and will not increase the deficit.

In a joint statement released Saturday, Deputy Premier Deb Matthews and President of the Treasury Board, and Yasir Naqvi, Minister of Community Safety and Correctional Services said:

“We are pleased that Ontario has reached a collective agreement with the Ontario Public Service Employees Union (OPSEU), with respect to the Correctional Bargaining Unit.

This final agreement is the result of much hard work at the bargaining table by both sides, with the assistance of mediator, Gerry Lee. The outcome is consistent with the fiscal plan as outlined in the 2015 Budget. This agreement supports the government’s ongoing efforts to eliminate the deficit while protecting the valued public services Ontario families rely on.

The agreement refers outstanding monetary issues to expedited mediation-arbitration. It also recognizes the essential work of our Correctional Bargaining Unit employees by providing a stand-alone collective agreement for future rounds of collective bargaining. Interest arbitration will also be provided going forward as a dispute resolution mechanism rather than the right to strike for the Correctional Bargaining Unit.

We will continue to work with our corrections staff as we move forward with our mandate to transform the correctional system to develop effective and lasting improvements to enhance rehabilitation and reintegration supports as we work to break the cycle of re-offending and improve the safety and security of correctional staff, inmates and the public. We look forward to returning to normal operations and moving ahead on that transformation together."”