Bus Éireann has banned workers who take sick leave from working on days which attract premium payments for three weeks afterwards - following what it said was a 24% rise in absenteeism in the last fortnight.
The move comes just ten days ahead of a threatened all-out indefinite strike over the implementation of a cost-cutting survival plan for the company without union agreement.
Bus Éireann recently revealed that it has an absenteeism rate of around 7%, which is about twice the national average.
However, the company said that in the last two weeks, absenteeism has spiked by 24%.
In a statement, it said: "Given the current financial crisis, any work which attracts premium payments (such as weekends) will not be afforded to those who report off duty due to illness - for a period of three weeks."
In a response to Acting CEO Ray Hernan, NBRU General Secretary Dermot O'Leary accused Bus Éireann of intimidation, provocation and reaching a new low in penalising those who fall ill.
He said the move could cost a worker €80 per rest day.
Mr O'Leary described the sanction - added to the stripping away of long standing arrangements in recent weeks - as an act of naked aggression, and using a sledgehammer to crack a nut.
The National Bus and Rail Union, along with other unions at Bus Éireann, has warned there will be an all-out, indefinite strike from 20 February if the company proceeds with cost-reduction measures on that date.
Unions insist that the cuts would reduce pay by up to 30%, while management says the cut would only amount to around 10%.
Union members pledge support for Bus Éireann staff
The prospect of the Bus Éireann dispute spreading to other CIE transport companies has increased after SIPTU members in Dublin Bus and Irish Rail pledged to support their colleagues.
After a meeting of SIPTU representatives from all three CIE subsidiaries, Sector Organiser Willie Noone said members in Iarnród Éireann and Dublin Bus were willing to take whatever appropriate actions were necessary to support their Bus Éireann colleagues - as they were all members of CIE companies, with corresponding conditions of employment and work locations.
Mr Noone noted that while there is already the prospect of strike action from 20 February, there is an increasing likelihood that school bus drivers could also be dragged into the row, with a consequential adverse impact on rural areas.
He said workers in Iarnród Éireann and Dublin Bus had given a strong commitment to display solidarity with Bus Éireann employees, because their conditions of employment were currently under "vicious attack".
Mr Noone also confirmed that SIPTU is finalising arrangements for a strike ballot at Dublin Bus after the company refused to make a recent pay increase pensionable from 1 February as agreed in a deal reached in October.
Dublin Bus workers to be balloted over 'breach of agreement'
In a statement issued this evening, the NBRU said it will ballot its members at Dublin Bus over "breach of agreement".
The NBRU is balloting members for strike action over the company's failure to make a recent pay increase pensionable from 1 February.
As part of a deal done to end last year's Dublin Bus dispute, it was agreed that a pay increase would not become pensionable until 1 February.
However, the company recently sought an extension of one month for what the unions had described as a "temporary accommodation".
Mr O'Leary said that the company was categorically informed that the NBRU would not accept such a request on the basis that it would materially alter the September WRC agreement to resolve the dispute without the consent of those who had already accepted the terms.
He concluded by saying that the union now intends to ballot its members immediately for industrial action up to and including all out strike.