CRH has excluded over 3,000 employees in the United Kingdom from the controversial election on European Works Councils. Elections for workers in five other countries are going ahead.
It is the first Irish company to exclude British employees from an EWC election by availing of the "opt out" from the Social Charter.
Under EU law, every company employing more than 1,000 people and with plants employing over 150 in at least two EU member states must establish an EWC. So far, 25 out of an estimated 250 transnational companies in Ireland have complied with the directive.
Two of the main Irish unions with the company have urged their members to vote `no' to the proposals because CRH failed to consult them before organising the ballot.
They say the proposed constitution allows only the management to call EWC meetings and the majority of changes likely to take place in the company are excluded from the EWC agenda.
The CRH ballot is due to conclude today and the count will be held on Thursday. It is being conducted by the Institute of Public Administration and the unions have been invited to attend the count, along with representatives of the Irish Congress of Trade Unions.
The unions are likely to contest the outcome if there is a majority in favour of the proposals but they could find this difficult. Under Irish law, the company's EWC constitution will be recognised as meeting EU requirements provided it registers the agreement by September 22nd and there is an absolute majority in favour among the 6,300 workers balloted.
CRH is the fourth largest employer in the Republic and the unions are concerned that it's EWC constitution could set a benchmark for other companies.
Under the proposed CRH constitution, the company has only committed itself to holding meetings when changes are being considered that affect at least 3 per cent of its entire EU workforce, or 10 per cent of those directly affected by the changes in plants in at least two countries.
The company's operations are highly fragmented. Its 2,450 Irish employees are scattered across 71 operations and its 3,713 employees in other EU states (outside Britain) work in 199 plants.
The industrial officer of ICTU, Mr Stephen McCarthy, said last night that CRH seemed to be adopting different approaches to the EWC provisions in each country.
CRH spokesman, Mr Clifford Hilliard, said the EWC directive is not appropriate for a company which is "a multiplicity of little businesses operating in a highly competitive market". None of the company's plants deliver its building products beyond a 30 mile radius.
The decision to exclude the UK workforce "wasn't anything more than recognising that Britain had not signed up for the Social Charter". He says that meetings of the EWC would be held at the request of worker representatives if the issues raised met the criteria accepted in the election.
