Householders will tonight complete the 2006 Census - the most important in the history of the state, it was claimed today.
The Central Statistics Office believes valuable information on Ireland's unprecedented demographic and social changes will be gleaned from data in over one million Census forms.
Government Chief Whip Tom Kitt said: "This is a particularly crucial Census. It is possible that the population could be as high as 4.2 million which would be the highest since 1871, 135 years ago."
"In recent years we are all aware of a much changing Ireland - an Ireland that has seen a huge influx of non-Irish nationals which has created a new, vibrant, multicultural society.
"For the first time, the Census will give us precise figures on the numbers of non-Irish nationals living and working here."
Mr Kitt pointed out that population statistics were essential for planning the provision of essential services such as health care and education at local and national level. They will also advise on employment trends.
"In addition the Census will inform us as to other more local needs such as retail outlets and social amenities. The results will greatly help the Government with special strategic planning," he added.
The minister reaffirmed the confidentiality of all information collected from individual households and businesses, pointing out that this confidentiality is guaranteed by law.
New questions on different family types, female fertility, ethnicity and voluntary activities will be included in questions this year.
The delivery and collection of the forms involves a total of 40 regional supervisors, 400 field supervisors and 4,400 enumerators in a nine-week operation costing €50 million.
