Yukon Employees Union president Steve Geick says he considers the move a lockout.
"Our people were in T-shirts, yes, but they were clearly identified as flight attendants," he said.
Air North president, Joe Sparling, says it's not a lockout. He says employees were sent home simply because they were out of uniform.
"They did show up to work, but it was their intention to not provide full service and their intention to not wear uniforms and that's not acceptable," said Sparling.
He says the flight attendants wore T-shirts that had his phone number on them. The flight attendant's website also includes Sparling's email address.
Geick says managers and non-union staff shared duties on the morning flights between Whitehorse and Vancouver. There's no word yet on how the situation will affect the airline's evening flights between the two cities.
On Monday, the union representing the flight attendants announced it would be taking job action after nearly a year of contract negotiations, with flight attendants withholding in-flight service on selected flights. The next bargaining session is scheduled for next week.