Dec ⁠12 (Reuters) – WestJet Airlines said on Friday it would ⁠pause its rollout of non-adjustable economy seats next week, testing the limits of add-on culture ⁠as it faces pushback for charging extra for adjustable seats.

Canada’s WestJet in October started flying newly ​configured 737 planes whose standard economy seats come in a ‍fixed reclining position. Adjustable seats are still available, but passengers must pay extra, sparking a backlash from some travelers, along with pilots and flight attendants who say the change could affect staff ​health and safety.

WestJet said in a statement it would pause the reconfiguration work following December 15 to make aircraft available during the peak winter travel season. By Monday, approximately half ​of WestJet’s all-economy fleet will be reconfigured.

“We will also be monitoring guest feedback ⁠and assessing the operational performance of the reconfigured aircraft to learn more ‌about how this product is performing in the market,” Calgary-based WestJet said.

The carrier added it ⁠would resume the rollout in the spring.

WestJet said ​in October that half the passengers who tested the new seats preferred ‌the fixed recline to avoid others encroaching on their space.

WestJet staff have questioned the comfort of the seats ‍in case they need to fly on them to commute.

“While WestJet has stated that (the) rollout is paused at approximately 20 aircraft, they have also indicated that the broader fleet is planned for this reconfiguration,” the union said in a memo to staff from late November seen by Reuters.

“The union will continue to press the operational, safety, and working condition impacts of this decision and advocate for a ⁠thorough re-evaluation.”

(Reporting by Allison Lampert in ‌Montreal; Editing by Chris ⁠Reese)