Migrant workers are helping to ease the pressure on firms struggling to recruit but many are being lured into the black economy, employment experts warn.
Around 130,000 people from eastern Europe have applied to work in the UK since 10 new countries joined the European Union (EU) on May 1 2004.
According to the Recruitment and Employment Confederation (REC) several sectors such as hospitality, catering and health are dependent on these workers.
REC research shows that demand for staff among UK businesses has risen continuously for 20 months with employers finding it increasingly difficult to recruit local or nationally.
Thousands, it says, are turning to immigrant workers to fill the gap.
It is estimated, for instance, that 2,500 care home workers have come from the new member states.
Gareth Osbourne, REC managing director, said: "Currently there are more than half a million job vacancies in the UK. However, there are simply not enough people in the UK with the right skills to fill these positions.
"This is leading to unsustainable wage inflation that will eventually price the UK out of key markets, such as manufacturing. Migrant workers have helped to ease the pressure, and without their presence, the problem would be more acute."
But REC warns that while many eastern Europeans are finding legal employment, some legitimate workers are falling into the black economy.
It blames the problem on poor support for migrants which forces them to seek income through alternative and illegal means.
Many fall foul to rogue employers who exploit them for their own financial gain.
"Support is needed from government to ensure that effective enforcement is in place to clamp down on rogue operators who flout regulations and supply workers to the black economy," Osbourne said.
