The latest cuts will result in the loss of 36 flights per week, 300 jobs and up to 300,000 passengers passing through the airport - in addition to cuts announced just three months ago at the airport by Ryanair.
Specific routes which will be affec
ted in their winter schedule from October 1 have not yet been disclosed by the airline.
A spokesperson for the airline said these will be announced closer to that date.
Chief executive Michael O'Leary warned in February last he expects Ryanair's base in Shannon to "get smaller and smaller" over the coming years, and he now appears to be fulfilling that promise.
The number of Ryanair aircrafts at Shannon Airport will now be reduced from four to three, while Dublin Airport has also been affected by the cut.
The no-frills airline has also warned that further cuts in their winter schedule will be announced in the coming months if the Government fails to abolish the tax, which came into effect on April 1.
"Ryanair will switch these aircraft and continue to grow in lower cost/no tourist-tax countries such as Belgium, Holland, Greece and Spain where governments have recently scrapped tourist taxes and airport charges to promote tourism," said a spokesman.
However, they added that if the tax is reversed by the Government, Ryanair will also reverse their decision.
Ryanair chief executive Michael O'Leary said the tax represents "tourism suicide".
"Price sensitive visitors are switching to lower cost destinations in Europe where governments welcome tourists, not tax them," said Mr O'Leary.
He predicted that the cumulative effect of cutbacks at both Shannon Airport and Dublin Airport would result in the loss of €750 million in tourism spend.
In February last, Ryanair announced the loss of five routes and two aircraft from Shannon Airport, with effect from March 30.
Routes to Berlin, Gdansk, Katowice, London Luton and Newcastle were axed in that period, resulting in the transfer of over 100 Ryanair jobs to other bases.
Ryanair said these cuts would result in the loss of 700,000 passengers per annum will also give rise to the loss of some 700 support jobs in and around Shannon Airport.
On that occasion, politicians were divided on whether the airline's cutbacks were truly in response to the new tax.
Labour Deputy Jan O'Sullivan said this "just shows how short-sighted the tax was", while Fianna Fail TD Niall Collins said the airline's rationale in pulling the services was "stretching credibility beyond breaking point".
As a result of the cut in services, the reduced passenger traffic at Shannon contravenes the five-year agreement signed between Ryanair and Shannon Airport Authority in 2005.
However, Mr O'Leary said reaching a traffic target of two million passengers per year at Shannon "was rendered null and void by the Government traffic tax".
Shannon Airport Authority was not available to comment at the time of going to print.
