It's still not clear when Air Canada might start flying again as the flight attendants union resolved Monday to push on with a strike but the airline expressed hope that it could get planes off the ground Tuesday.

The strike officially began just before 1 a.m. ET on Saturday, and Air Canada locked out flight attendants about 30 minutes later due to the strike action.

The union representing Air Canada flight attendants says it intends to remain on strike in defiance of a back-to-work order from the Industrial Relations Board. The challenge to the order to return to work by Sunday 2 p.