WestJet is apologizing to about 260 passengers after a flight from Toronto to London was cancelled twice this weekend due to maintenance problems.

The apology comes days after WestJet's CEO Gregg Saretsky said the airline's expansion to Europe is "among the most successful things we've done," despite mechanical problems and passenger complaints.  

Lauren Stewart, spokesperson for WestJet, said in an email early Sunday that Flight 3 from Pearson International Airport to Gatwick Airport was cancelled on Friday due to a "non-scheduled maintenance issue." It was cancelled again on Saturday due to "completion of the maintenance" but is expected to proceed on Sunday night.

Stewart said the airline has provided hotel and meal vouchers to passengers stranded by the cancellations on Friday and Saturday.

"WestJet sincerely apologizes to our guests for the inconvenience and thanks them for their patience and understanding," she said. "We understand their frustration and are working diligently behind the scenes to rectify the situation."

The airline has created another "flight segment," WS4303, to ensure all passengers are able to reach their destination and said it has booked remaining guests on another carrier, Stewart said.

Stewart said the airline has made arrangements to ensure the passengers are as comfortable as possible while they wait for the plane to be fixed.

"In terms of numbers, we do not provide our flight loads however you can probably surmise from the fact that the 767s hold around 260 guests and the flights are relatively full that we are caring for quite a number of guests at the moment."

Some of the passengers took to Twitter to express their anger and to report that they are stuck at the airport.

WestJet bought four wide-body aircraft to start flying across the Atlantic about a year ago. On average, the planes are 24 years old and had several mechanical issues, leading to flight delays and cancellations. 

Last week, Saretsky blamed the early problems on the repair company hired by Boeing to fix the planes.

Each cancelled flight, or flight delayed more than four hours, costs the airline approximately $225,000 in compensation to passengers, if the plane is full. 

Gregg Saretsky WestJet

WestJet president and CEO Gregg Saretsky says of flights to Gatwick: 'From Day 1 we've been full.' (CBC)

With files from Shanifa Nasser