TORONTO - Air Canada customer service and sales staff say they're willing to walk off the job Monday night if the airline doesn't budge on key concessions.

Hundreds of workers and labour rights activists rallied at Toronto's Pearson airport today, a day before one of Air Canada's unions could serve notice of a strike.

Disgruntled workers brandished placards outside the domestic departures section of Terminal 1, chanting for the airline to give them "a fair deal."

A proposal to change pension plans for new hires is a key issue as Air Canada (TSX:AC.B) and the Canadian Auto Workers union continue bargaining in Toronto.

The CAW, which represents 3,800 Air Canada customer service and airport workers, could serve 72 hours notice on Friday for a strike beginning at midnight on Monday.

If bargaining fails, the airline says it plans to maintain full operations by implementing a contingency service to minimize the impact on customers.