More than 10,000 Air Canada flight attendants are set to strike from Saturday morning over "poverty wages" and unpaid labour, triggering what experts have dubbed "the most severe North American shutdown in decades".
The carrier began cancelling flights on Thursday and predicts a full shutdown on Saturday.
Edinburgh Airport will bear the brunt of disruption alongside London Heathrow and Manchester, with Glasgow and Birmingham airports also likely to be affected.
The strike will disrupt between 18 and 28 flights from the UK each day, according to air passenger rights company, AirAdvisor. It said that it will impact up to 5,600 passengers flying from the UK.
Edinburgh Airport operates daily flights to Toronto Pearson Airport, while Glasgow Airport serves Montreal and Toronto through direct services and codeshares. Glasgow Airport also offers flights to Montreal.
The industrial action is indefinite, with no end date, fliers have been told.
Anton Radchenko, Aviation Expert and Founder of AirAdvisor, said: "This strike is a perfect storm for UK-Canada travel. Passengers aren't just losing flights, they're losing time, money, and in some cases, once-in-a-year holiday plans."
"Air Canada’s UK routes are some of the most premium in the transatlantic market, and a near-total shutdown sends shockwaves across both leisure and business travel."
Radchenko recommends passengers check their flight status daily and consider refundable alternatives via New York, Boston, or Reykjavik.
"Keep receipts for any out-of-pocket costs, from meals to hotels, as Canada’s APPR rules require airlines to cover reasonable expenses for delays or cancellations within their control," he said.
He added: "If you must travel during the strike days, aim for early morning departures when disruption is typically lower, and avoid tight connections. For those who can, consider pushing non-essential trips by a week.
"Not only will stress levels drop, but you may also save significantly on fares once the initial rebooking rush subsides.”
Sources used: "Edinburgh Live", "WalesOnline", "Daily Record", "AirAdvisor" Note: This article has been edited with the help of Artificial Intelligence.