ISME has said that SIPTU's position in the partnership process is untenable after the union announced details of a one-day transport strike next Thursday March 18.
The business lobby group said the strike will have severe implications for businesses and the tourism sector and could lead to further job losses.
Chief Executive Mark Fielding claimed that the decision to strike amounted to no more than inter-Union rivalry and coming the day after Patrick's Day was an attempt to cause as much embarrassment to the Government as possible.
Speaking today, Fielding said: "This action is an affront to the public and business community, who are once again at the mercy of the bully boy tactics of the trade union movement.
"The timing, the day after Saint Patrick's Day, has obviously been scheduled to cause as much embarrassment as possible to the Government, at a time when many foreign guests will be in the country.
"The impact, however, will be to totally undermine the tourism industry at one of its busiest times of the year and consequently put jobs in jeopardy," he added.
Fielding also claimed that if justification for transport privatisation existed next week's strike action provided it.
He called on the management of SIPTU to immediately disengage from strike action and maintain negotiations with the Independent talks Chairman Kevin Foley in order to finally bring a resolution to the ongoing dispute.