Ryanair may axe more than 100 pilots and at least 200 cabin crew as it plans to cull its Dublin winter fleet by a fifth.

Union members blasted the announcement as "reckless and unnecessary" and "belies recent Ryanair statements that industrial action... has had no impact on the company’s operations".

The threat to jobs come days after the low-cost carrier attacked pilot strikes, also labelling them as "unnecessary".

Ryanair will reduce its Dublin aircraft numbers from 30 to “at most” 24 for winter 2018. As a result, notice has been served on pilots and other staff “whose services may not be required from October 28 onwards”.

Aircraft will be transferred to Poland later this year, to be used by Ryanair’s Polish charter airline, Ryanair Sun.

The airline’s chief operating officer Peter Bellew said he “regretted” the possible job losses in “country markets where business has weakened or forward bookings are being damaged by rolling strikes by Irish pilots”.

Forsa, the union representing the pilots, said today's move demonstrated Ryanair's "unwillingness and/or inability" to follow through on promises to agree working conditions with staff.

"Today’s announcement [is] a provocative gesture which is likely to harden pilots’ resolve," a Forsa statement read.