A veteran Fine Gael TD has said immigration has been good for Ireland as the country needed to “expand our gene pool” . Olivia Mitchell claimed immigration in the Celtic Tiger years has already resulted in physical improvements.

The deputy for Dublin South, warned of the dangers of reducing the diversity of the population’s genetic stock during a Dáil debate on the new requirement to register father’s names on children’s birth certificates.

“It is unacceptable that even as recently as last year, 2,675 children were born and registered without a father’s name on their birth certificate. I presume the number is roughly the same every year,” she said.

Ms Mitchell said if fathers remained living in the same area over a number of years and had more children it was quite likely two of those children might meet without being aware of their shared parentage.

“[This] raises the possibility of relationships outside the permitted degree and certainly outside what would be wise. As a small island country we should be expanding our gene pool, not reducing it,” she said.

Contacted by The Irish Times about her comments , Ms Mitchell said she believed that the “mobilty of races” had had a positive impact on Ireland.

“I think as an island country cut off from the rest of Europe, it’s a good thing that we have a certain amount of immigration. Mobility of races is a good thing,” she said.

“You can even see the better-looking and taller children now as a result of the Celtic Tiger years. I think it’s a good thing to keep our IQs up there; it’s not just about appearance.”