Ryanair says the Government's latest green list announcement is 'shambolic', and that it should employ students instead.
It comes after just seven countries made the updated travel list on Thursday.
From Monday people can travel from Cyprus, Finland, Germany, Iceland, Latvia, Lithuania and Poland without having to isolate for 14 days when they arrive in Ireland.
Meanwhile Hungary, Italy, Slovakia, Greece, Norway and Estonia were removed from the list.
Ryanair CEO Eddie Wilson told Newstalk Breakfast: "It's another shambolic announcement by Government yesterday.
"On Tuesday they said they were going to adopt the European traffic light system - they then deviated from that, picked a number of 25 out of the air.
"We've now excluded the Greeks and the Italians, we're 60% less.
"An Inter Cert student or a transition year student - they should employ one of those to look on the European Centre for Disease Control website: the numbers are there.
"There is no need for this whatsoever, excluding countries that are 60% less."
"The EU list is there, if they implement it 21 of the 27 countries people can travel freely.
"And again Ireland missed the boat last July, and now they're going to do it again".
"This industry is about confidence: people travel on the basis that when you get off an airplane, or you book on an airplane, that when you get to the other end you know what paperwork you need, etc.
"And what's happening now is, from yesterday's announcement, they're going to take Italy and Greece off the list - and in two weeks' time when they finally get around to adopting the EU regulations, they're going to put them back on again."
"They're going to wreck the travel plans of people this weekend, and then what's going to happen is they're going to put those countries back on in two weeks' time: why can't they just do it now?"
Meanwhile Ryanair has announced it is cutting its October capacity by a further 20%, on top of a 20% cut already announced in mid-August.
The Irish carrier said it now expects its October capacity to fall from 50% to some 40% of its 2019 levels,
However the company said it expects to maintain a '70%+' load factor at this reduced schedule.
Ryanair said these capacity reductions were necessary due to "damage caused to forward bookings by continuous changes in EU government travel restrictions and policies, many of which are introduced at short notice, which undermine consumers’ willingness to make forward bookings."
It added: "In some countries (most notably Ireland), where the Government have maintained excessive and defective travel restrictions since July 1st, COVID-19 rates have risen in recent weeks to 50 per 100,000 population - more than double those of Germany and Italy - where intra-EU air travel was freely permitted since July 1st".
A Ryanair spokesperson said: "While it is too early yet to make final decisions on our winter schedule (from November to March), if current trends and EU governments' mismanagement of the return of air travel and normal economic activity continue, then similar capacity cuts may be required across the winter period."