A new report has found that migrant workers in Europe tend to be segregated in low-paid jobs which offer limited opportunities for upward mobility.
The report, drawn up by the European Foundation for the Improvement of Living and Working Conditions (Eurofound), also says that migrant workers are more likely to suffer unhealthy working conditions, to work longer hours and to perform shift work, night work and weekend work.
The report maintains that migrant workers are also more frequently exposed to discrimination in the workplace by supervisors, colleagues, customers or patients.
It says that migrants are playing an increasingly important role in the labour markets of EU states.
However, the disadvantages that they experience represent a major challenge to social and labour market policies in European countries.
Eurofound's director, Jorma Karppinen, said in a comment on the report: "The recruitment of migrant workers plays an important role in the economic development in Europe and migrant workers play an increasingly important role in EU labour markets.
"Although there is increasing awareness of the crucial role played by migrant workers in fostering economic growth, greater attention needs to be paid to their working and employment conditions."
The report says that in most countries, migrant workers tend to be segregated into unskilled occupations.
They were also found to be more likely to perform undeclared work.
Despite being a particularly vulnerable segment of the labour force, migrant workers were often poorly represented by trade unions.
The report states that migrant workers face higher unemployment rates and, when employed, are more likely to be over-qualified for the jobs that they do.
The report says that this represents a "significant waste of human capital and considerable inequality".
The report maintains that the poor working conditions of migrant workers can be linked to difficulties in obtaining work permits, even in countries where there are labour supply shortages.
The report also points out that migrant workers "face obstacles in acquiring citizenship and can thereby be excluded from access to such skilled occupations as public-sector employment, the professions and business activity".
The report suggests that citizenship should become easier to acquire or that "the connection between citizenship and entering into specific occupations should be eliminated".
The foundation is a European Union body, established by the European Council to contribute to the planning and design of better living and working conditions in Europe.