Sandra's story illustrates one kind of discrimination facing migrant workers: the denial of family reunification.

A Nigerian psychiatric nurse and programme manager, the 43-year-old was promised by an Irish recruitment agency that her children could join her once she settled here. So, four years ago, the recently widowed Sandra said goodbye to 16-year-old Peter and 10-year-old John, leaving them with her father.

"It was very hard, but I felt I would see them soon," she says. "I lived in the nurses' home, spent no money, took all the overtime I could get, and with the savings I brought with me, finally put a deposit on a house outside Dublin.

"I applied for a visa for my children, but 18 months later I was told that John could come, but not Peter, as he had just turned 18. I presented my case to an Irish politician, who said: 'It takes a parent with a heart of stone to go to Africa, uproot one child and leave the older one waving at the airport while the plane takes off.' But I had to do it because the younger child's visa was going to expire while I appealed for the other."

Sandra was subsequently told that Peter could probably enter Ireland on a student visa if she could prove he had a college place here with paid-up fees. She fulfilled these criteria, again working long hours to save the 2,500 fees for a computer course for her son, and furnishing the Department of Justice with all the relevant papers.

"They wrote back saying 'insufficient documentation', and also that my son could overstay the visa, work here illegally or move to another common area," says Sandra. "Then the college said they would refund only 10 per cent of the fees, which is terrible.

"John is on his own when I am at work, which is most painful. The plan was that Peter would be here to look after him. My father has since died and Peter lives with a cousin, but I am very worried about him. We were very close, but it is difficult to maintain the relationship at such a distance. I am very traumatised and upset all the time. It is very hard.

"I appealed the student visa decision to the Department of Justice, who said they would look into it - but that was last March. If I could talk to the Minister I would ask him to reply to my letter, but even though I am a strong woman, I am very much afraid I would not be able to say anything and would probably just cry."

Sandra's real name has not been used