For years the only competition CIE has had to face is internally, between the National Bus and Railworkers' Union and SIPTU. But trying to negotiate major change with the two unions has been a serious handicap, as it has seemed at times that the only aim of the two unions has been to rival each other's militancy.

In the past relations between full-time officials, as well as shop stewards, were acrimonious. One senior SIPTU negotiator once told this reporter he would "burst into flames" if he darkened the portals of the NBRU office in Parnell Square. Rather than drop in on the NBRU general secretary, Peter Bunting, he walked another 200 yards to the nearest SIPTU office to phone him.

Since he was appointed national industrial secretary of SIPTU in 1998, with responsibility for CIE, Noel Dowling has not made a single public criticism of Bunting, although the men have had some frank exchanges in private. Born in Mullingar 51 years ago, Dowling has come up the hard way. He has no problem telling his own members home truths, let alone other trade unionists, management or politicians.

This week, when Iarnrod Eireann slid into chaos, compounding the impact of the Dublin Bus strike, it was Dowling who negotiated the return-to-work settlement. He has also held the line in Dublin Bus, resisting pressure to serve strike notice while allowing members not to pass the NBRU pickets.

In the past it has been Peter Bunting who has largely dictated industrial relations strategy in Dublin Bus and Bus Eireann. Born in Belfast 49 years ago, he once trained as a Christian Brother. Since then he has taken a degree in politics and business at Trinity College Dublin, and is studying by correspondence for a master's in industrial relations at Keele University. Nobody questions the professionalism or authority of his submissions to the Labour Court.

Bunting first made a name for himself as one of the rank-and-file leaders of the five-day strike in 1979, which saw bus workers win a pay rise of £10.50p a week. Subsequently he succeeded the NBRU's legendary founder, Tom Darby, as general secretary.

The union began as a breakaway from the old Irish Transport and General Workers' Union in the 1960s. The latter is now subsumed in SIPTU. The NBRU has about 2,500 members among the 9,700-strong CIE workforce. It has a majority of the drivers in Bus Eireann and Dublin Bus, and of the locomotive drivers in Iarnrod Eireann.

The NBRU is not a member of the Irish Congress of Trade Unions and was not a signatory of Partnership 2000 or the Programme for Prosperity and Fairness. Consequently it has a one-item agenda - to win the best deal possible for its members. That simple focus has been one of its great strengths within the CIE union structure.

In contrast, until recently SIPTU had regional structures that made it hard to develop a strategic focus for enterprises such as CIE, which are organised throughout the State. Dowling is one of three national industrial secretaries appointed by the union in 1998 to address that problem.

He has plenty of experience under his belt as a trade unionist and political activist. After working in Britain in jobs as varied as building work and accounts, he returned to Ireland and became a full-time union official with the ITGWU in 1978.

His union brief has also been varied, ranging through private and public sector employments, including Aer Lingus, which is one of the toughest patches for SIPTU officials. He was national nursing officer for the union during the 1997 nurses' dispute, and the author of the proposal for a Nursing Commission which headed off a national strike that year.

Politically he shares Bunting's republican socialist background. He was a Workers' Party activist for many years and now describes himself as a nominal member of the Labour Party.

This weekend both men must agree a joint industrial relations strategy to advance their members' interests in Dublin Bus. They know that without it they have no hope of achieving the massive improvements in pay and conditions that will make public service driving a decently paid and pensioned occupation in the capital.

They have the experience and expertise to do so. Bunting will probably find it harder to work in harness than Dowling. He is more prone to adopting a high-risk strategy and engaging in the odd dramatic flourish.

But as Dowling proved with the rail dispute earlier this week, a slow but sure approach may ultimately take the drivers further.