The dates of the All-Ireland football and hurling finals have been targeted for strike action by disgruntled rail workers.
National Bus and Rail Union (NBRU) members have voted in favour of four days of stoppages at Iarnrod Eireann, with the first two coming on August 24 and 25.
They will then strike on the day of the hurling final on September 7 and on September 21 when the footballers line out.
These are among the busiest days of the year for rail travel.
Some 80pc of balloted NBRU members voted for industrial action up to and including strikes.
It comes as Iarnrod Eireann plans to implement pay cuts ranging from 1.7pc to 6.1pc.
The company has argued the cost savings of €16.9m are essential to secure its viability and has been supported in its stance by the Labour Court.
In a letter to employees yesterday, chief executive David Franks reiterated that the company faces insolvency without "urgent action to correct" its finances.
But the NBRU and SIPTU both voted to reject any cuts. Other unions have accepted the latest proposal. Iarnrod Eireann will implement the measures from August 24.
"Our members have rejected proposals to reduce pay over three separate ballots, we have been consistently telling the company and the Government that our members will not subsidise their own jobs," NBRU general secretary Dermot O'Leary said.
Expecting a 2014 rail service on 1998 subvention levels was "just not tenable", he added, referring to reductions State funding. He insisted workers "don't want at all to shut any services down".
SIPTU previously announced a one-day stoppage on August 25 and its members will also begin a work to rule on August 24.