The budget airline said that a six-month trial on 100 routes showed that some seats were in particular demand – those on the front two rows in order to guarantee a quick exit, and over-wing seats because they boast more leg room.

The company said: “The optional service allows passengers to pre-reserve seats in the front two rows, for a quick getaway on arrival, or in over-wing rows (16 and 17), which provide greater legroom, and has proven to be very popular with Ryanair passengers during its summer 2011 trial.”

The airline added that its Priority Boarding service would continue to run at a cost of €5 (about £4.30), and that those with priority boarding or reserved seating would be allowed to board the aircraft first.

Rival budget carrier easyJet has also unveiled plans to introduce reserved seating.

The cost of reserving a seat on an easyJet flight is unclear, but a trial is set to go ahead in spring 2012.

Chief executive Carolyn McCall told Travel Weekly: “We will roll it out further only if it works operationally, from a revenue perspective and increases passenger satisfaction. If it doesn’t, we won’t.”