There could be trouble looming on the horizon for Toronto's transit system as the TTC faces a potential labour shortage with the deadline approaching for employees to get the jab.

TTC employees have just a few weeks left until the October 30 deadline for full inoculation under the transit agency's September-issued vaccination mandate, and there is already potential fallout materializing well before the deadline.

A letter sent to Amalgamated Transit Union Local 113 leaders by TTC chief operating officer Jim Ross and obtained by the Toronto Star on Thursday reveals that transit operators will have to wait a bit longer than normal to apply for their November shifts.

The Star quotes the letter as stating that the bump is necessary for the TTC "to adjust our service and crewing requirements based on the anticipated reductions in available workforce following the vaccination deadline."

Okay, well, that doesn't sound good.

So what does this mean for customers? A union representative told The Star that these labour shortages could translate to even more crowding on TTC vehicles.

Though the TTC has yet to make any statements on how unvaccinated employees will be handled after the October 30 deadline, there is still steadfast resistance to the policy.

Local 113, which represents approximately 12,000 TTC employees, has been vocal in its opposition to the transit agency's policy.

Union leaders have been pushing for an alternative to the TTC's vaccine mandate, including tabling a proposal for a vaccination policy offering antigen testing as an alternative to vaccination. Similar approaches are being taken in Brampton, Mississauga, and Hamilton.

TTC CEO Rick Leary announced in August that the TTC would offer rapid testing as an alternative to vaccination, but he would flip-flop on the issue shortly after, drawing strong words from Local 113.

A statement from the union issued earlier in October reads, "days later, with no warning, he changed course to implement an extremely strict vaccination policy which is unreasonable and ineffective."

Between ATU Local 113 and TTC CEO Rick Leary, only the union has been consistent in its approach to vaccinations. Click the link to read ATU Local 113 President Carlos Santos' update to members.https://t.co/zAYqX870SK

— ATU Local 113 (@ATUlocal113) October 1, 2021

The statement goes on to state that the union believes "mandating vaccination as a term of employment violates the Collective Agreement, Charter and privacy law. We are committed to fighting this issue at grievance arbitration if TTC does not reconsider the Policy."

This back and forth between the TTC and union shows no signs of slowing, with ATU Local 113 recently accusing TTC management of rejecting all of their counter-proposals and "picking unnecessary fights with workers" to distract "from TTC's failure to put in place measures to keep transit riders and workers safe."