The new system means passengers who want to take two cabin bags onboard have to pay for priority boarding, enabling them on to the aircraft first and giving them access to the overhead lockers.

Those travelling without priority boarding will still be able to take bags on the plane, but their larger bag will have to go in the hold meaning they then have to wait the other end for their baggage to be unloaded.

Priority boarding is on offer to passengers as late as 30 minutes before their flight takes off.

Ahead of the rule change, Ryanair’s chief marketing officer Kenny Jacobs said: “This new policy is centred around lower checked bag fees and bigger bag allowances and we have notified by email all our customers travelling from Monday.

“All Ryanair customers will still be free to bring two free carry-on bags but we will now ask non-priority customers to put their bigger bag in the hold – free of charge – in order to eliminate boarding delays and improve our industry leading on-time departures.

“Ryanair has already introduced new reduced checked bag fees (from €/£35 to €/£25) and increased check-in bag sizes (from 15kg to 20kg) to encourage more customers to check in bags and reduce the number of customers with two bags at the boarding gates. We hope our customers will enjoy this new and simplified bag policy.”