Gratitude is a weak and short-lived emotion. In the mid-1990s, SIPTU persuaded Aer Lingus workers to accept the Cahill Plan. It provided for several hundred redundancies and a pay freeze.

Without the cutbacks, the state-owned airline might not have survived, let alone continued to employ 5,000 and now be preparing for a flotation.

As a consequence of the plan Aer Lingus moved from being a flagship employer to part of the low-wage economy. What is more, many of its staff, particularly cabin crew, have been recruited since the Cahill Plan. They are not interested in the past. They are interested in the here and now.

This scenario can be painted right across Irish industry and SIPTU is not the only union affected by it. To a greater or lesser extent every affiliate of the Irish Congress of Trade Unions is experiencing the same problems. The positive side of social partnership was saving old jobs and creating new ones. The negative side has been policing the system and ensuring wage restraint is enforced.

What makes SIPTU's problem particularly difficult is that, with 200,000 members, it embraces the whole spectrum of the workforce. Every move must be carefully calculated to ensure a gain for some members does not imply a loss for others. That is why it has put so much emphasis on "social wage" issues such as the National Minimum Wage and tax reforms, which benefit everyone.

The position paper put forward last month by the union's new vice-president Mr Jack O'Connor represented a fairly seismic shift in union policy. In it he advocated that SIPTU seek a specific pay increase as an element in the review of the Programme for Prosperity and Fairness (PPF) - 5 per cent was the guideline figure, depending on inflation rates and tax changes in the Budget. The paper also showed the mounting pressure on the union from its members because of the rise in inflation.

Mr O'Connor returned to the charge at last week's Dublin regional conference of the union.

"Interestingly, the contrasting definitions of `success' - the employers and ours - are coming to the fore," he said.

"For us growth has never been an end in itself, but rather the means to the attainment of good living standards and a better quality of life. For almost a decade and a half it was possible to travel parallel paths with the employers and the Government when economic solvency and the restoration of growth was an agreed priority.

"But for some time now we have passed the point where these problems remain the central issues."

Far from the PPF being part of the solution he now believes it could now be part of the problem. The catalyst for this turnaround is inflation.

What makes inflation such a problem for SIPTU is that about 28 per cent of its membership earns less than the average industrial wage. These are the workers who suffer most from price rises and benefit least from tax cuts and social welfare increases.

Many Aer Lingus cabin crew fall into this category. The starting rate is just more than £5 an hour and it takes 24 years to reach £10 per hour.

One reason for the mass defection of SIPTU members to its rival, IMPACT, was a perception among the dissidents that SIPTU was "too cosy with the company". IMPACT, which has rapidly developed a strong profile in the aviation sector through the affiliation of pilots and airport management grades, seemed a better option.

Aer Lingus has been somewhat dismayed by this turn of events, but to some extent it has only itself to blame by long delaying pay claims from all employees. Mr O'Connor is careful not to blame cabin crew for the situation.

"When companies want to survive they will co-operate with you but when things improve and it comes to the point of how profits are distributed they don't want to know. Workers, including Aer Lingus workers, are the victims of that approach."

So are unions. Membership transfer rows between unions are nothing new but they appear to be increasing. It would be hard to over-estimate the bitterness and potential for damage of the dispute about who represents cabin crew.

Mr O'Connor firmly blames the company for a situation that has "pitted worker against worker and union against union". If the pattern should spread he foresees a situation that could "undermine the 1959 decision to merge the two Irish congresses of trade unions" - in other words a split in the ICTU.

The finding by ICTU's disputes committee this week in the Aer Lingus cabin crew dispute appears to have averted the immediate danger of such a split. The committee censured IMPACT for taking cabin crew into membership and balloting them for industrial action while the ICTU investigation was still under way. It did, however, allow IMPACT to retain the 1,056 members who had fully transferred from SIPTU until September 29th.

The ICTU finding would seem to rule out any further transfers, but there are indications that at least some SIPTU cabin crew may seek to challenge this.

Whichever union cabin crew find themselves in, there will be no magic wand to wave away the problem of low pay. But there is no doubt about the depth of disillusionment felt by many SIPTU members with their union. For its part, SIPTU cannot absolve itself from blame by pointing the finger at others - especially as members in other grades are also openly considering defection.

While the amalgamation of the Irish Transport and General Workers Union with the Federated Workers Union of Ireland to form SIPTU in 1990 has worked very well at national and regional level, it has been less successful in developing a consistently high quality service either at local level or across industrial sectors. The recent turbulence at CIE, which saw the formation of a breakaway union for train drivers, is the most striking example of this. SIPTU also has a structure that is so democratic it is regularly plunged into election campaigns for general officers, national and regional executives. As a result, the divide between policy debates, organisational reforms and servicing members can become extremely blurred.

There are no easy solutions to SIPTU's problems. The danger is that if the right answers are not found relatively quickly, its present cold could give the rest of the trade union movement pneumonia.