The city of Montreal and the firefighters' union have reached a tentative agreement on several longstanding labour disputes including their pensions.

These issues go back several years to the introduction of Bill 15 in the National Assembly.

In August 2014 firefighters ransacked City Hall while police officers stood by and watched.

That day of violence led to the suspension of 57 employees and the firing of six firefighters.

Now, three years later, negotiators say they have reached an agreement in principle.

The exact details are not being revealed, but they affect retirement and the pension plan in according with the provision set out by Bill 15.

It also requires an end to all pressure tactics by firefighters regarding pensions, and puts an end to the legal matters involving the August 2014 ransacking.

The firefighters will get a chance to vote on this contract offer during a general assembly in the next few days.