The Government should examine the option of regularising the status of undocumented immigrants living here, according to a former Fianna Fáil minister.
Noel Davern, who retired from the Dáil at the last election, remains chairman of the Irish delegation to the parliamentary assembly of the Council of Europe.
The assembly will today debate a report urging governments to look into the possibility of introducing regularisation programmes.
Mr Davern said he was not opposed to the idea of an amnesty programme, but said any effective scheme would have to be co-ordinated across European countries.
"A uniformity programme would be great. It's a bigger issue in some countries.
"Spain is in a tough position - it's a huge burden for them. Some of these countries [ on the Mediterranean] receive many more immigrants.
"I think we have to share the responsibility," he said.
Asked if he supported the idea of a regularisation programme in Ireland, Mr Davern said: "I wouldn't be against it".
At a conservative estimate there are over 5.5 million irregular migrants living in the European Union, and the report notes that it is "increasingly clear" that a large proportion of these migrants will remain in Europe and cannot be returned to their countries of origin.
"It is therefore essential that member states of the Council of Europe examine how they should handle this large number of persons who live in the shadows of European society, largely tolerated but without legal status or the right to remain, and often subjected to the worst forms of exploitation," the report states.
Minister for Enterprise and Employment Micheál Martin said in August that the Government planned to launch a research project to try to determine the number of people working illegally in Ireland.
The Migrant Rights Centre Ireland has estimated that of the 1,000 migrant workers who sought its support last year, about a quarter had become undocumented. Almost all had entered the country legally on a work permit.
In the last 25 years, more than 25 regularisation programmes have been carried out within the European Union, providing four million undocumented migrants with either temporary or permanent residence and work permits.
Those in favour argue that such schemes encourage circular migration, lessen the likelihood of exploitation, reduce the size of the underground economy and have a positive impact on tax revenues and the collection of social security contributions.
Critics claim the schemes reward lawbreakers and attract more illegal immigrants.
In Spain, some 570,000 migrants were regularised by an amnesty in 2005.
Urging governments to learn from the experience of past programmes, the Council of Europe report cites the Spanish example as one from which others can learn.
"Within Spain the regularisation programme has been welcomed by irregular migrants, by civil society, by employers and trade unions as well as by the majority of politicians," it says.
One of the Spanish scheme's main failings, however, was Madrid's failure to keep its European partners aware of its plans to carry out such a programme. "This led to misunderstandings . . . and also created a backlash against regularisation programmes in a number of countries across Europe."