Divisions between unions can damage the cause of solidarity between workers, the Taoiseach has warned.
"They undermine the shared pursuit of sustainable improvements in living and working conditions.
"Unnecessary divisions between employers, unions and government and other social partners equally act against national solidarity."
He was speaking last night at the launch of James Connolly - A Full Life by former Ictu general secretary Donal Nevin.
The launch in Liberty Hall was picketed by about 30 supporters of the so-called Rossport Five and anti-deportation activists, some of whom jeered the Taoiseach as he entered the venue.
Mr Ahern said a key milestone in Irish trade unionism was the unification of the movement into one congress in 1959. Subsequent strengthening of the movement had been key to the achievements of social partnership between government and the unions.
"The continuation of this spirit of trade union solidarity remains crucial to Ireland successfully meeting the many shared challenges that lie ahead in the next phase of our national development."
He said Connolly's achievement in bringing a European and international perspective to the cause of ordinary Irish working people resonated today.
In aligning the goal of national development with a commitment to social justice and solidarity, it was clear that Connolly's legacy could remain a source of inspiration for many years to come.
He praised Mr Nevin for providing "an extensive journey" of the patriot's era, and for painting "a vivid picture of the many personalities of the time".
