Eastern Europeans are becoming the mainstay of hard-to-fill jobs in Britain's rural areas, research published on Tuesday says.
Many workers from new EU states work in agriculture, the TUC found
But Trades Union Congress report also warned that employers are still prepared to exploit migrant workers.
The TUC study found more than 40% of workers from the new European Union states settled in rural counties.
Just under a quarter went to London, reversing the trend of earlier migrants to settle in urban areas.
TUC general secretary Brendan Barber said the research suggested migrant workers were filling a different role from that of their predecessors.
"It points to big changes in the rural and small town economy in recent years that have left an unmet demand for low paid labour.
"EU expansion has allowed these jobs now to be filled legally by Eastern European workers. But too often employers are trying to get away with denying them their rights or exploiting them."
Workers from the 10 eastern European states which joined the EU in May must register with the Home Office within a month of their arrival.
They are then sent a registration certificate and a leaflet from the TUC.
The TUC's report analyses those who followed up on the leaflet and contacted the union for advice on tax and employment matters.
In the six months from May to October 2004, it was contacted by 1,600 Eastern European workers.
The greatest number - 60% - were from Poland, followed by Slovaks at 13% and Czechs at 9%.
The most popular counties for the new arrivals were Lincolnshire, Norfolk, Kent and Sussex.
Those who went to London were most likely to settle in the borough of Haringey in the north of the capital, the study found.
The report makes a number of recommendations, including that workers should be provided with more detailed information on taxes and benefits.
It also calls for progress on the EU's proposed Agency Workers Directive so that employers can no longer use agency workers on less favourable conditions than those enjoyed by the permanent employees.
The report comes ahead of a TUC conference on migrant workers on Wednesday where Home Secretary David Blunkett will deliver the keynote speech.