The battle to win over Canadian coffee drinkers has launched an air campaign with McDonald's move to sell its coffee on WestJet flights starting today.

Starting Monday and moving toward full implementation by December 1st, McDonald's will be the only coffee available on 650 WestJet flights, serving an estimated 30,000 cups of coffee a day across all of the airline's fleet of 140 Boeing 737 and 767 jets. The program will soon expand to WestJet Encore, the airline's regional service.

"We've always believed that the sky is the limit for McCafé – and today this officially rings true," McDonald's Canada's president and CEO John Betts said in a release. "We're proud that Canadians have welcomed McCafé into their homes and daily routines, and now our partnership with WestJet lets us take this connection to even greater heights for Canadian coffee lovers."

The coffee will be served in a custom-made cup with a "special McCafé and WestJet design" and will be free of charge, along with other refreshments such as water, soft drinks, juice and tea.

The cups will also feature the fast food chain's loyalty program, with a peelable sticker point and loyalty card on every cup. Cappuccino and lattes won't be offered because the aircraft doesn't have a machine to steam milk.

The move is the latest front in an all out war in the coffee industry to win Canadians loyalty in their coffee buying. Tim Hortons was once untouchable in the space, but McDonald's has made inroads with its free coffee promotions.

Second Cup is the exclusive coffee provider on Air Canada flights, and Toronto-based regional carrier Porter Airlines uses Starbucks exclusively.

WestJet CEO Gregg Saretsky said Monday that Tim Hortons and Starbucks Canada both tried to bid for the contract to serve coffee on WestJet's flights, but were unsuccessful.

When asked if WestJet will co-brand with McDonald's on other products such as Chicken McNuggets, Saretsky said: "Possibly. We really want to make sure we get the coffee right first."

Tim Hortons does not currently have a deal with any airlines to be the provider of coffee on board.