OTTAWA -- City council has approved a plan to offer transit service at no cost to the riders in the month of December if the city's beleaguered light rail system is up and running.

Mayor Jim Watson first announced his plan to propose free ridership in December on the CTV News at Six on Sept. 21, following the LRT train derailment outside Tremblay Station that has kept the system shut down for nearly a month.

The plan passed by a vote of 17 to 6, with councillors Rick Chiarelli, Diane Deans, Mathieu Fleury, Catherine McKenney, Jeff Leiper, and Carol Anne Meehan voting against it.

The mayor said at the time that no-charge transit in December would be a way to apologize to transit riders who have had to deal with a service that he called substandard.

Watson said the money to cover a month of service at no charge to the passengers of OC Transpo buses, the LRT and ParaTranspo would come from the funds that would have been sent to the Rideau Transit Group. The city has the power under its contract to withhold funding from the consortium that built and maintains the Confederation Line if a certain level of service is not met.

Staff estimate it would cost $7.2 million to make ridership on the city's transit system free for a month.

However, the mayor noted during council debate Wednesday that the free month of service would only come into effect if service on the LRT has resumed by then. If not, it will be delayed until the month following the resumption of service.

There is no timeline for a return to service for the Confederation Line, which has been closed since the Sept. 19 derailment. The Rideau Transit Group will present the city with a return-to-service plan, which must be vetted independently by Philadelphia-based TRA Inc.