Many Eastern European immigrants in the UK are harder working, more reliable and motivated than their British counterparts, according to a Home Office report.
More than 345,000 East Europeans have arrived seeking work since the EU expanded to include former Soviet bloc countries on 1 May 2004.
Employers compare them favourably with UK workers, according to the first study of attitudes to migrant workers since EU expansion.
The report said that low-skilled UK workers were unwilling to take jobs in low-skilled areas because the pay, conditions of work, hours and nature of the job were unfavourable.
Migrant workers were considered by employers to have a number of advantages, most notably their work ethic, which employers found more acceptable, the report said.
They were often cited as harder working, more reliable and motivated than domestic workers. Without them, some businesses in the low-skill sector claimed they would not survive.
Immigrant workers are often preferred over Britons in the agriculture, catering and hotel industries. They are happier than Britons to be paid the minimum wage because it is higher pay than they can earn in their home countries.
However, the report warned that, anecdotally, there were reports of migrant workers being exploited. They were receiving lower pay than domestic employees, worked long hours and had poor conditions.