A suggestion by the Taoiseach that Irish construction workers are not prepared to work in bad weather was dismissed yesterday by a union leader as "off-the-wall".
Mr Eric Fleming of SIPTU said Irish workers operated in appalling weather conditions, and Mr Ahern was "badly advised" if he thought otherwise.
Irish work practices were identified by Mr Ahern last week as one of the things that would have to change if the building of a metro in Dublin was to be made affordable.
The factors making such a project much more expensive in Dublin than Madrid, he said, included "contingencies for wet days, dry days, frosty days, foggy days".
Madrid is particularly hot and dry even by Spanish standards, so it is unlikely the building of a metro there would be delayed by wet weather.
Mr Fleming, who is also secretary of the construction industry committee of the Irish Congress of Trade Unions, said it was impossible to carry on construction work in some Irish weather conditions. Nevertheless, Irish building employees did work in the rain and paid a heavy price for it, he said.
Research carried out last year showed there was an alarming prevalence of rheumatism, arthritis and lumbago among Irish building workers, probably as a result of working in wet weather, he said.
"I'm asking for major research into this issue because it is a serious problem."
Mr Fleming said more care was taken in other countries than in Ireland to shelter construction workers from the effects of inclement weather.
"The Taoiseach is off-the-wall there. Irish workers do work in the rain, and the proof is that they are sick as a result. A lot of them have had to leave the business because of it."
Mr Fleming stressed, however, that he welcomed the Taoiseach's apparent willingness to address the profiteering which was adding hugely to the cost of building projects.
Speaking in Greece on Friday, Mr Ahern cited environmental and planning rules, overpriced construction materials and high professional fees as other reasons why the Dublin metro was currently impossible to build.
He also emphasised the fact that in Madrid work on building the metro was carried out 24 hours a day, whereas that would not be the case in Ireland under current circumstances.
Mr Fleming said Irish workers had no objection to doing shift work on a 24-hour basis and would be delighted to see the metro project going ahead.
Mr Ahern's comments were also positively received by the Construction Industry Federation. A spokesman said it would welcome "any initiative that would speed up the whole planning process and get projects more quickly from the planning to the construction stage".