Ryanair boss Michael O’Leary has issued a warning to staff that hundreds of jobs could be at risk following a slump in quarterly profits and Boeing 737 Max delivery delays.

The no-frills airline’s chief executive told employees in a video message that Ryanair has 900 more staff than required, and that job losses will be announced in the coming weeks.

He claimed that the “increasing likelihood” of a no-deal Brexit in 12 weeks’ time had added to the challenges facing the carrier, and was likely to have a damaging effect on its UK and Ireland bases.

“We are worried that this will have a particularly damaging effect, particularly on our UK bases and on some of our Irish bases which are heavily dependent on travelling between Ireland and the UK,” he said.

More:Ryanair suffers fall in profits amid Brexit concerns

New Ryanair Boeing 737 Max emerges with new name

Ryanair warns of base closures and cuts due to 737 Max delays

O’Leary said: “We already have a surplus of over 500 pilots and some 400 cabin crew, because resignations have dried up to effectively zero since January 2019.”

He added: “We will need about 600 less pilots and cabin crew for summer 2020” due to delayed 737 Max deliveries.

“I am sorry to advise you that this means we have to cut our aircraft numbers – and our staffing – not just in summer 2020, but also in winter 2019.”

The 737 Max is grounded worldwide over concerns with its software following two fatal crashes in Indonesia and Ethiopia.

Podcast: Is the aviation sector in turmoil?

O’Leary said job cuts would take place around the end of September and again after Christmas.

Ryanair would start briefing staff and unions “in the next week or two”, but that final decisions about the losses are not likely to be made before the end of August, ahead of the winter schedule.

The airline reported a 21% drop in profits in the last quarter to €243 million on Monday, blaming lower fares combined with higher fuel and staff costs.