The Irish Locomotive Drivers' Association is expected to call on members to opt out of the new agreement for drivers, when it holds its annual conference this weekend.
Such a move would prevent the introduction of new summer rosters on many routes. Iarnrod Eireann is planning to introduce the rosters from the end of May.
The ILDA has the majority of drivers at depots in Ballina, Westport, Sligo, Athlone, Dundalk, Drogheda, Rosslare Harbour and Dublin's Inchicore depot.
The last provides drivers for the Arrow suburban routes, while the other depots supply drivers for the east coast from Rosslare to Belfast and for much of the west and midlands.
The union is also expected to call for a renegotiation of the annualised hours agreement concluded by Iarnrod Eireann with SIPTU and the National Bus and Railworkers' Union.
The biggest sticking point for ILDA members appears to be a requirement that Sunday working be a regular feature of the basic working week and will not attract double-time premiums as it does at present.
Returns from a questionnaire distributed by the ILDA to members is expected to show that train-drivers are prepared to work on Sundays, but only if they can be guaranteed the right to a number of Sundays and bank holidays off each year, as well as overtime premiums. This would represent a major setback for the company.
Iarnrod Eireann almost doubled train-drivers' pay to £29,500 and offered them a five-day week on the basis of consolidating overtime into a maximum 48-hour week. At present many drivers work in excess of 60 hours a week to boost their incomes.
The ILDA executive secretary, Mr Brendan Ogle, said yesterday that unsocial-hours working would be a major issue at the conference, as well as rail safety and the status of train-drivers. He accepts that many people see the ILDA as adopting a negative position to change in Iarnrod Eireann but says that after the conference the union would be outlining its proposals for a better service.
The ILDA is Ireland's newest and smallest trade union. It was set up in September 1998 and has only 119 members. However, this represents over 40 per cent of mainline train-drivers in the Republic, giving it potential industrial muscle out of all proportion to its size.
To exercise that muscle it must acquire a negotiating licence. It received a major setback two weeks ago in the High Court when it lost a claim to be recognised as an '`excepted" body. Excepted status is granted to relatively small organisations seeking to represent workers within one employment. It is currently considering an appeal to the Supreme Court.
In the meantime it is expected to continue its campaign to win a negotiating licence as a trade union. It has been accepted for registration by the Registrar of Friendly Societies and has lodged £20,000 in a deposit account, thus fulfilling two of the three requirements.
The third will be harder to achieve. This is a minimum membership of 1,000, and there are only 250 train-drivers in the Republic, or 300 if DART drivers are included. ILDA has had discussions with DART drivers but has so far not engaged in any recruiting campaign there.
It has even withdrawn an invitation for DART drivers to attend this weekend's conference as observers. Some mainline drivers believe that the acceptance of direct recruitment into the DART from other grades in Iarnrod Eireann marks the beginning of de-skilling. The fact that a DART driver can be trained in 16 weeks, as opposed to 16 months for a mainline driver, underlines the point.